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Getting Started In Wetplate Collodion PhotographyBy Joseph Smigiel

Fig. 1 An original 1/6th-plateambrotype, c. 1860.Historically, the popularity of the wetplate process was short-lived. From its inventionby Frederick Scott Archer in 1851 the process flourished until the introduction of dryplates in the early 1880s. The process was safer and more convenient than itspredecessor the Daguerreotype, and much sharper than its contemporary the Calotype,but wetplate collodion still required the proximity of a darkroom and the preparation,exposure, and processing of the plate all within a matter of minutes. The convenience ofdry plates which could be prepared in advance and processed long after exposure quicklyled to the abandonment of the wetplate process by most studio and locationphotographers. Its use did continue for a while longer by street photographers doingtintypes, and this practice even continues today in some developing countries.Today, a wetplate revival is occurring, sparked largely through interest in Living Historyand the imaging revolution centered around digital technology. As journalistic,commercial, and amateur photography markets have shifted towards digital, fewerconventional products remain available. This shift has led some art photographers torediscover the beautiful wetplate collodion process.Aside from the ever-present safety issues of the process, having a darkroom nearby isthe largest hurdle to overcome when attempting wetplate collodion. For those withconvenient access from studio to darkroom, the problem is minimized. For fieldwork,another solution must be worked out and this generally takes the form of a portabledarkbox or darktent that accompanies the itinerant photographer. Some modernworkers have also converted SUVs or enclosed trailers into mobile darkrooms. I’ve goneso far as to convert an old Class-C motorhome into one.

BEFORE ATTEMPTING WETPLATE COLLODION PHOTOGRAPHY, BE SURE TO FAMILIARIZEYOURSELF WITH THE CHEMICAL HAZARDS ASSOCIATED WITH THIS PROCESS. SEVERALCHEMICALS USED IN THE PROCESS ARE EXTREMELY HAZARDOUS, EXTREMELYPOISONOUS, CARCINOGENIC, EXTREMELY FLAMMABLE, AND/OR POTENTIALLYEXPLOSIVE.

BEFORE ATTEMPTING THIS PROCESS, READ THE MSDS INFORMATION AND SEEKCOUNSEL FROM TRAINED PROFESSIONALS (CHEMISTS, HAZARDOUS MATERIALHANDLERS, SPECIALIZED PUBLIC SAFETY OFFICERS, ETC.) WHO ARE FAMILIAR WITHPROPER HANDLING AND DISPOSAL OF THESE CHEMICALS.THE AUTHOR AND PUBLISHER OF THIS ARTICLE DO NOT ACCEPT ANY RESPONSIBILITYOR LIABILITY RESULTING FROM ERRORS, OMISSIONS, OR THE IMPROPER USE OF THESECHEMICALS BY OTHER INDIVIDUALS. USE OF ANY CHEMICAL MENTIONED IN THISARTICLE IS AT YOUR OWN RISK.

My Introduction to Wetplate CollodionA few years ago a major manufacturer of photographic supplies announced thediscontinuance of my favorite 35mm film and the photographic paper I used almostexclusively for my work. This was shortly followed by the elimination of my favoritesheet film in the format I use most frequently. With that emulsion also unavailable at thetime in the ULF format I use, and my general disinterest in the rising digital imagingtechnologies, I decided to become more self-reliant in regard to photographic materials.With a longstanding interest in alternative photographic processes, producing work inmedia such as Van Dyke Brown, gum bichromate, and the POP/albumen/salted paperprocess offered familiar means to produce personal photographic prints independent ofthe photo factory. However, the camera emulsion choice remained problematic. Wouldevery film I chose soon be discontinued or rendered useless for alternative printing dueto “improvements in the manufacturing process” as several popular sheet films hadsuddenly been subject?It was about this time that I happened upon a short online PBS video of Sally Manndiscussing the wetplate collodion process. I was enthralled as she demonstrated workingthe process in the field out of the back of her SUV. Her movements appeared ritualisticas she held a glass plate to the sky and coated it with the syrupy collodion solution.She talked reverently of learning the process from a master, Mark Osterman of theGeorge Eastman House. I sensed there was a modern heritage forming and I knew atthat moment I wanted to become part of the modern-day wetplate revival and itslegacy.

Fig. 2 A black glass ambrotype portrait of JohnCoffer holding a 20x24 steel tintype sheet.

I began gathering all I could read on the subject and found several workshoppossibilities. It quickly became apparent that most workshop leaders had learned the

process from either Mark and France Osterman, or from John Coffer (Figure 2), himself afriend of early wetplate revivalists George Berkhofer and John Hurlock. The modern webof wetplate practitioners radiate from this central core of individuals who continue topractice wetplate, teach, and publish relevant to the field.For my initital workshop, I chose to study with NY fashion photographer Michael Mazzeoat Peter’s Valley Craft Center in the Delaware Gap region of New Jersey. Michaelreceived his tutelage from both the Ostermans and John Coffer. Michael ran us throughthe fundamentals of chemical formulation, safety, glass preparation, and finally, thechemical steps involved in sensitizing, exposing and processing the wet plates. Now Iwas really hooked. PVCC provided a great workshop teacher, a wonderful setting in thePoconos, great food, and the opportunity to network with some extremely talentedartists.After some moderate success at the PVCC workshop I continued to practice mytechnique and began to get images I enjoyed. I had heard so much by now about JohnCoffer that I decided to do a follow-up workshop with the Grand Master. Armed with a bitof previous experience, John quickly helped me refine and simplify my technique. Hewas also a great host on his farmstead in the Finger Lakes district of New York State. Ihad a great time learning from John and returned later in the year to his “TintypeJamboree,” an annual gathering of practicing wetplaters from around the globe.Most experienced wetplaters recommend purchasing a basic instructional text (seebibliography), studying it intensely, and then seeking out a workshop from anexperienced practitioner. I agree with that approach. While not particularly difficult,wetplate collodion is a very hands-on endeavor, and watching a master perform thesteps really is the best way to learn the process. There are some subtleties to theprocess best learned from direct observation. And of course, workshops also tend to be agood place to network and meet people of like kind. The modern wetplate crowdcertainly is diverse and interesting.

A Brief Overview of the Wetplate Collodion ProcessWhile many variations exist with formulas, equipment, and technique, the wetplatecollodion process generally entails the following:1) The wetplate collodion process requires a working-strength salted collodion solution, asilver nitrate sensitizing solution, developer and fixing solutions, as well as varnishes andintensifying or reducing solutions. These baths should be prepared in advance. (Formulasfor each are listed later in the article.)2) Prepare a japanned steel or enameled aluminum metal plate, or clean a sheet of glassto act as a substrate for the collodion emulsion.3) Pour the salted collodion onto the plate to cover it evenly with the emulsion, and drainthe excess back into the pouring vessel. The collodion film will begin to set as thesolvents evaporate from the surface. It is important to let the collodion set and form a“skin” for approximately 15-30 seconds before proceeding to the sensitization step. Ifthe plate is placed in the sensitizing bath too soon, the collodion film will partiallydissolve and be ruined. This will also contaminate and adversely affect the sensitizingbath. On the other hand, if the plate is withheld too long, the film will becomeimpervious to further chemical action and will not sensitize or develop properly.

The following two steps are done under deep amber or red safelight illumination:

Fig. 3 An open wetplate holder.4) Immerse the plate into the silver nitrate sensitizing bath. Most sensitizing baths arehoused in a lightproof box to enable the photographer to safely leave the darkroom oncethe plate is submerged in the tank. The plate needs to sensitize between 3-5 minutes onaverage. Sensitizing is sufficient when the silver nitrate flows off the surface of the plateuniformly without beading or forming irregular rivulets. Upon sufficient sensitization, theoriginally transparent collodion film will take on an opaque creamy appearance.5) The sensitized plate is removed from the silver bath, the reverse carefully wiped toremove excess fluid, and then it is placed in a special lightproof wetplate holder (Figure3). Note that the plate is placed in the holder and exposed while it is wet (hence thename “wetplate” collodion). The photographer usually has a 5-10 minute window fromthe time the plate is removed from the sensitizing bath through camera exposure anddarkroom development before the emulsion solvents (ether and grain alcohol) evaporateand the collodion film becomes impervious to the processing solutions. This timeframevaries with heat and humidity as well as the particular collodion formula used.6) The plate holder is brought to the camera which has been previously set-up in regardto framing and focusing on the subject. The subject should be illuminated by UV richsources (e.g., northern skylight, sunlight, fluorescent lamps, etc.). The sensitivity of theplate will extend from UV through blue wavelengths. The spectral sensitivity may beextended slightly through the use of various halogen salts in the collodion formulas.7) An exposure is made and the darkslide replaced. Due to the low sensitivity ofcollodion, exposures may run into seconds outdoors during daylight hours. Becausecollodion is primarily sensitive to ultraviolet radiation and because it is relativelyinsensitive to light, exposure meters are generally not used and exposures aredetermined by trial-and-error at first, and then by experience later on. Plates destined tobecome negatives should receive at least 1 stop more exposure than their positivecounterparts. (Negatives are also typically developed for a longer time in weaker, lessactive developers.)8) The plate holder is returned to the darkroom for processing.

The following steps again require deep amber or red safelight illumination:

9) The exposed plate is removed from the holder and is either transferred to adevelopment tray, or, more commonly, the plate is held horizontally in one’s hand.10) A minimum volume of developer solution (see ferrous sulfate formulas) is pouredover the plate and development is timed to about 15 seconds for positives, or 90seconds for glass negatives. (Exposure of subsequent plates is adjusted to bring theplate development times into these ranges.)11) Water is flowed over the developed plate until all traces of developer have beenremoved. This may be done by rinsing the plate in hand or in a tray with severalchanges of water until the water flows off the plate uniformly without forming rivulets orstreaks on the collodion surface.

It is now safe to bring the plate into normal lighting conditions.12) The plate is fixed for twice the time it takes to clear in a solution of either sodium(hypo) or ammonium thiosulfate (rapid fixer), or a weak solution of potassium cyanide(KCN).

Note that potassium cyanide is a deadly poison and special care must be taken whenusing this chemical. It must not be ingested nor come into contact with broken skin, andthe mixture of any acid (such as found in the developer) with the KCN solution generateslethal hydrogen cyanide gas. The latter is the chemical used in the gas chambers duringthe Holocaust of WWII. Small amounts of hydrogen cyanide gas will be continuallyreleased from potassium cyanide solutions, and when (and if) detected has an odorsimilar to roasted almonds. This chemical should be used only in well-ventilated areas.KCN imparts a slightly warmer coffee-and-cream color to the plate, works faster, washesout easier, and produces a slightly brighter positive image with a bit more contrast.However, due to its extreme toxicity, the difficulty in obtaining it, and the specialprecautions needed to safely handle and dispose of this chemical, I do not recommend itsuse by anyone learning the process. Beautiful results may be obtained using conventionalthiosulfate fixers.

13) The plate is washed in several gentle changes of water over a period of severalminutes to remove the fixer.14) The plate is dried either passively in a drying rack or slowly over the gentle heat ofa paraffin lamp.15) A protective varnish is poured over the dried plate, the excess drained, and thevarnish solvent evaporated by slowly heating the plate evenly over a paraffin lamp.16) Finished plates are generally sealed under glass in protective frames or cases.Ambrotypes on transparent glass will need to be backed with a dark material in order toproduce the characteristic optical reversal to a positive image.

The Wetplate Collodion Darkbox and Other Specialized Equipment

Fig. 4 A conventional 5x7 sheet film holderconverted to wetplate use.

In addition to items such as trays, mixing graduates, and other equipment commonlyused in photographic darkrooms, the wetplate process requires a few specialized items.

Though modern view cameras can be retrofitted with special wetplate backs and plateholders, it is also possible to adapt dryplate holders or modern sheet film holders for usewith the process (Figure 4). The latter will work to get one started using the processwithout investing a great deal of money on wetplate camera equipment. But, it isprobably best to eventually invest in a dedicated wetplate back and holder for reasons ofconvenience of operation and to help maintain the condition of favorite cameras. Silvernitrate dripping from the sensitized plates will stain and eventually corrode camera partsand lightrap materials.

Fig. 5 An inexpensive KodakBrownie 3B box camera adapted for ¼-platewetplate use.

Inexpensive antique Brownie box cameras and modern Holga “toy cameras” may also beused with surprising results. The Brownie cameras exhibit remarkable sharpness andpicture quality. Modifying a Brownie camera is very simple (Figure 5). Note that onlymetal plates can be used in these simple cameras. Glass plates are too thick and preventthe camera backs from closing correctly.Collodion and ether will dissolve some plastics. Therefore, glass graduates as well asfunnels and storage and mixing vessels should be used for the collodion and ethersolutions. (Conversely, potassium cyanide, if used in the process, should never be storedin glass containers.) In addition to avoiding plastics with the ether and collodionsolutions, neither should ever be poured down a sink drain. Ether fumes in municipalsewer systems would present a danger and any collodion could congeal and clogplumbing very efficiently.

Fig. 6 A handmade acrylic chemical tank andplate dipper.

For the sensitizing and fixing steps, most wetplaters use specially constructed tanksinstead of darkroom trays (although the latter may be employed). These tanks are fairlyeasy to construct from acrylic sheet. The silver sensitizing tank is usually housed in aninclined lightproof box or outer shell to prevent exposure of the plate. A “dipper” made

from acrylic is also used to lower and raise the coated plates into these baths (Figure 6).For reenactors concerned with period correctness, glass tanks are usually employedinstead of modern plastics.

Fig. 7 A “helper tray” made of castacrylic sheet used for developingwet collodion plates.

“Helper trays” (Figure 7) made of acrylic may be used to facilitate development of theexposed plates. These handmade trays help minimize spillage of chemical solutionspoured onto the plates during processing. Many wetplaters prefer to simply hold theplates in hand during processing. With practice, the latter method tends to producehigher quality results and minimizes solution volumes used. Too much developer pouredtoo rapidly in one area of the plate may physically remove the emerging image.

Fig. 8 A handmade acrylic tank thatdoubles as a plate washer and storagetank.

Specially constructed plate boxes and drying racks are useful items to have on hand.Plate boxes may be fabricated from both wood and acrylic (Figure 8). The acrylic onesdouble as a wash tank and are useful for transporting wet plates home from the field forfurther processing when time or resources in the field are restrictive. Conventional blackplastic darkroom papersafes may also be used to transport large wet plates home. Thepapersafes are stackable and hold sufficient solution to prevent the plates fromdessicating and becoming impervious to further processing. Other workers constructspecial trays for “glycerizing” plates in the field to prevent dessication. Information onthat process can be found in most texts devoted to wetplate work.Drying racks turn up in flea markets and antique shops at reasonable prices or they maybe purchased new from a couple of wetplate camera sources. Though I haven’t triedthem, I imagine commom kitchen dish racks of similar design could be used for dryingphotographic plates.Speaking of kitchen stuff, obtain a 3-minute egg timer for monitoring plate sensitization.

Fig. 9 A lightproof tent of my own design.

Fig. 10 The interior of the darktent.A hydrometer is used to measure the specific gravity of the silver sensitizing bath inorder to keep it replenished correctly. As plates are run through the tank, silver iscombined with the iodide and bromide salts in the collodion film. This reaction causesthe silver bath to weaken in strength thus requiring replenishment. The hydrometerhelps bring the solution back to proper strength. Due to the constant release of etherand alcohol as well as salts coming off submerged plates into the silver solution, thespecific gravity changes due to these contaminants. The bath will never be as pure as itwas initially, but the hydrometer at least provides some useful feedback.Expensive lab hydrometers are not needed and may actually complicate themeasurement process. Hydrometers of sufficient accuracy may be purchased ataquarium supply shops as well as stores that sell brewery supplies.Finally, a portable darkroom is needed for most location work. Lightproof tents are oneoption, but they tend to be expensive to commission and bulky to use with aninvestment in time to set up (Figures 9 & 10).On the other hand, those with carpentry skills and a few tools will find construction of acollodion darkbox an easy weekend project. Designs vary and include the plans found inJohn Coffer’s Doer’s Guide for period darkboxes, manufactured designs available fromthe Star Camera Company, and individualized darkboxes such as the one I constructed.My darkbox is a Transformer-like thing on wheels incorporating a sensitizing tankdropped through the base of the box to allow large 10”x12” plates to be sensitized withinthe small suitcase-sized enclosure (Figures 11, 12, & 13).

Fig. 11 Using a portable wetplatedarkbox on location.

Fig. 13 My portable darkbox in thetransport configuration.

Fig. 12 A dimensional diagram (side view) ofthe homemade darkbox shown in Fig. 11.

Click images to see larger version andmore information.

Preparation of the Plate

Fig. 14 The ambrotype effect.Japanned metal plates (steel sheets coated with baked ashpaltum) were used historicallyto create inexpensive positive collodion images known as “tintypes” or more properly,“ferrotypes.” While Civil War Reenactors strive to attain period correctness in equipmentand materials by making genuine ferrotypes, preparation of authentic japanned plates istime-consuming and messy. As a result, many modern wetplaters use prepared black-enameled sheets of aluminum as the image substrate. Extremely convenient andinexpensive, the aluminum plates can be cut to size by suppliers such as Main TrophySupply. The aluminum plates have a thin cellophane-like cover that is peeledimmediately before pouring the collodion. This greatly reduces dust and resultantartifacts on the finished plates. Due to the thinness of the material, images made onmetal sheets are generally backed by a “tablet” of glass in the plate holder. This glassbacking-sheet prevents the spring holding the collodion plate to the focal plane frombending the metal sheet and throwing it out of focus.Sheets of glass are also used to make positive collodion images known as ambrotypes,as well as glass negatives from which prints can be made. The difference between thetwo variations depends on the density of the image. Ambrotypes are reallyunderexposed collodion negatives that reverse their tonality when backed by a darkmaterial or when made on dark colored glass (i.e., “ruby ambrotypes,” Figure 14).Collodion negatives and positives are virtually grainless.

Fig. 15 A handle-mount glass cutter and glasspliers recommended for dimensioning glassplates.

The initial preparation of the glass involves cutting the plates to size and then sanding orusing a whetstone to dull the edges of the plate (Figure 15). The roughening shouldresult in an approximate angle of 45° for the glass edge around the surface to be coated.This abrasion serves two purposes.First, it minimizes the hazard of cutting the skin on sharp edges of glass. (And this isparticularly important to avoid if the photographer uses potassium cyanide as the fixer.

Sharp or broken glass and a lethal chemical is a recipe for disaster. Additionally, ifpotassium cyanide is used as the fixer, it should never be stored in glass containers.)Second, the roughened edge helps adhere the collodion to the slick glass surface.The glass used for ambrotypes or negatives must be immaculately clean in order toprevent image artifacts and peeling of the film. The glass is typically cleaned using asolution comprised of whiting or rottenstone (both varieties of fine calcium carbonate)mixed in a solution of alcohol and water. A bit of solution is poured onto the plate andrubbed around to remove oil and dirt on the glass. Care must be taken to remove alltraces of this alkaline cleaning solution to prevent contamination of the expensive silvernitrate sensitizing solution. I like to use small lintless PEC Pads to clean the plates. Thesespecial pads will clean many plates before they need to be discarded.Some collodion formulas containing cadmium bromide and/or cadmium iodide are tenderand tend to lift from the surface of the plate. Adding a subbing to the surface helpsprevent this defect. The most common subbing is egg albumen mixed with a smallamount of water and spread about 1/8” in from the edge of the plate with a cotton swab.Immediately before coating the glass plate with collodion, the surface should be brushedto remove ubiquitous dust.

Pouring the CollodionThe use of thin, chemically-resistant gloves is strongly recommended when pouring thecollodion, in subsequent steps involving sensitizing the plate in silver nitrate, andadditionally throughout the development process. Wetplate is historically referred to as“The Black Art” due to the silver nitrate stains that identified early practitioners. Inaddition to the staining potential, silver nitrate is corrosive and may cause blindness ifconcentrated solutions are accidentally splashed into the eyes. Because of thesehazards, the use of chemically resistant gloves and protective goggles is recommendedwhen handling this chemical.Pouring the collodion properly is a skill that comes with some practice. Novice wetplatershave a tendency to use insufficient collodion solution in their initial pours. Too littlesolution causes irregular coatings and blank “islands” lacking emulsion on the finishedplates. It is far better to use too much collodion and have some spill over the edge ofthe plate than to use too little.Collodion has the approximate viscosity of warm maple syrup or cream and practice withsuch a substance can safely and inexpensively facilitate the learning process.

Fig. 16 The “waiter tray” method.Pouring the collodion can be done in normal illumination in proximity to the darkroom ordarkbox. However, I find it easier to pour in the darkbox.To pour the collodion properly, the plate is held as horizontal as possible using one ofseveral methods. For small plates, it is probably easiest to pinch one corner betweenthumb and forefinger and pour the solution with the other hand. For moderate sizeplates, the “waiter tray” method supporting the plate from below may be best approach(Figure 16). With larger, heavier plates, a combination of one of the two previousmethods while supporting the opposite corner on a table may be required.When coating the surface should have a fairly large pancake-like pour of collodion in thecenter of the level plate. The plate is then gently inclined towards the photographer so

that the fluid moves towards the near corner without flowing off the edge or touching thefingers holding the plate. Once the near corner is covered sufficiently, the plate is gentlyinclined to the adjacent nearest corner, then downward to the third corner, and finally tothe “pour-off” corner. As the fluid approaches the last corner, the plate is quickly turnednear vertical with the final corner placed inside a vessel used for containing the solution.

The plate is rocked back and forth while the collodion drains into the collection bottle.This helps minimize lineations and irregular thicknesses in the collodion film. The entirecoating operation should only take a few seconds to complete. With larger plates, it maybe necessary to add additional solvent (ether or grain alcohol) to the formula in order tofacilitate pouring and delay the setting up of the collodion film prematurely. You’ll noticethat solvents are continuously evaporating from the plate once the pour begins.Evidence for this evaporation is found in the obvious ethereal fumes and the rapidcooling of the plate in hand.

Ether HazardTo minimize the evaporation of solvents from the storage vessel, be sure to cap the bottles assoon as possible. Also, be sure to perform this coating step far away from any flame orignition source as the collodion/ether fumes when concentrated can be dangerously explosive.Ether has a low flash point and becomes ignitable at concentrations as small as 1.9% of thetotal air volume. Use the collodion only in well-ventilated areas (outdoors or indoors withproper explosion-proof ventilation systems specifically engineered to safely eliminate volatilehazardous fumes). Ether is also heavier than air and so fumes may sink to the ground surfaceand travel some distance before dissipating. For this reason, it is imperative to store andhandle ether and collodion away from ignition sources such as water heaters, furnaces,surfaces radiating heat, electric fans and other devices which may produce an ignition spark.Store these solutions outside of residences in cool, dark, and preferably explosion-proofcabinets or special laboratory refrigerators.It should also be noted that while the collodion and ether have a longer shelf life whenrefrigerated, such storage should only be done in explosion-proof refrigerators. Regularhousehold refrigerators should not be used to store these potentially-explosive chemicals.Should fumes accumulate, any spark from the fan motor may ignite the concentrated fumesand cause an explosion.Also, because of its potential to form explosive peroxides, opened bottles of ether should bedisposed of as soon as possible. Industrial and institutional guidelines generally recommenddisposal of ether within 3-6 months of opening under optimum storage conditions. Thisassumes oxygen within the container has been minimized using glass marbles to displace anyair within the storage vessel or by using a gas blanket specifically employed and formulated todisplace air from the surface of the volatile fluid. Any ether stored beyond this timeframeshould be considered dangerously suspect and handled only by individuals trained in the properhandling and disposal of explosive compounds.The addition of alcohol or special chemicals (e.g., antioxidant BHT) help stabilize ethyl etherand inhibit peroxide formation. To minimize any hazard associated with ethyl ether, it is bestto purchase only small quantities that will be used immediately and not stored. Recentexperiments by wetplate photographers indicate that grain or denatured alcohol may besubstituted for any additional ethyl ether called for in various collodion formulae. Suchsubstitutions eliminate the need to purchase and store ethyl ether and as a result, are stronglyrecommended for individuals practicing wetplate photography.Note however that denatured alcohol is poisonous and not suitable for consumption. Prolongedexposure to fumes of denatured alcohol should also be avoided for health reasons. Because ofthe health concerns associated with use of denatured alcohols, the more expensive 190 proofethanol is recommended as a substitute for ethyl ether in collodion formulas. I do usedenatured alcohols for cleaning labware, but I minimize my exposure to this chemical withgood ventilation and I always wear chemical-resistant gloves when handling it.

Wetplate Collodion FormulasSalted Collodion

Prepare the salted collodion by adding iodide and bromide salts, grain alcohol and ethylether to plain collodion. (Note: flexible collodion will not work. You must obtain and useCollodion USP in these formulations.) Most salted collodion solutions need to ripen forseveral days before use.For safety reasons, the substitution of 190 proof ethanol or denatured alcohol issometimes recommended in these formulas in place of any additional ethyl ether. Sinceethyl ether is extremely volatile, highly flammable, and potentially explosive, collodionformulas should be mixed and stored away from ignition sources (open flame, hotplates, electrical fans, etc.).In general, working collodion solutions contain approximately 1.5% bromide salt andslightly more than double that amount of an iodide salt. Common anions of these saltsinclude potassium, ammonium, cadmium, lithium, zinc, or sodium ions. Collodionformulas containing only potassium bromide and potassium iodide salts will clear quicklyand be ready to use the same day, but their keeping properties are reduced. On theother hand, cadmium collodions may take several days to ripen, but will age moreslowly. Ammonium salts also are used in quick-clearing formulas but they may produceirritating fumes and shorten the life of the working collodion as well.Iodides add speed to collodion while bromide salts extend the spectral sensitivity andproduce lower contrast results with a finer gradation in midtones. As any collodion agesand turns from light straw to red in color, the contrast generally increases and the speedof the emulsion decreases.Addition of either potassium bromide or potassium iodide in the formula will also causeany bromidized collodion to throw down a precipitate which may take several days toclear.

Potassium bromide and potassium Iodide are essentially insoluble in ethanol and so mustbe dissolved in a minimum amount of distilled water before being added to collodionformulas. Care must be taken to use the minimum amount of water because 190 proofethanol already contains 5% water and collodions can only tolerate a certain percentage.If too much water is present, the nitrocellulose (aka pyroxyline) will precipitate out ofsolution. Warming the water will help dissolve iodide salts.

Carey Lea’s Landscape Collodion Formula #7This is a double-cadmium salt collodion that has a long storage life and a slightly greaterspectral sensitivity than some other formulas. Because cadmium salts are used, thecollodion tends to be more fragile and has a tendency to lift from the plate surface.Subbing the plate edge with cotton swab saturated with albumen helps adhere thiscollodion film to the plate. Note that cadmium salts are carcinogenic and should behandled using appropriate personal protection equipment.Traditional Lea’s Landscape #7Stock Alcoholic Bromo-Iodizing Solution:In a clean bottle capable of holding at least 125ml(~4oz) mix:190 Proof Grain Alcohol (Everclear orsimilar) 100 ml

Cadmium Bromide 1.5 gAmmonium Bromide 1.3 gCadmium Iodide 3.4 gAmmonium Iodide 2.6 gFirst, dissolve the cadmium bromide in the alcohol.Then, dissolve the ammonium bromide into thatsolution followed by the other two salts.Working strength collodion formula:In a clean bottle capable of holding at least 250ml(~8oz) mix:

Alcoholic Bromo-Iodizing Solutionfrom above 40 ml

190 Proof Grain Alcohol 50 mlEthyl Ether 30 mlCollodion USP solution (~6%pyroxilene collodion) 120 ml

Due to storage concerns and the difficulty obtaining diethyl ether, many wetplatephotographers substitute either grain or denatured alcohols for any ether other than thatinherent in the Collodion USP as purchased. Such low-ether mixtures may contain morewater than usual due to its presence in the grain alcohol. The additional presence ofwater in the collodion may result in tender films, reduced adhesion to plates, and theneed to extend the interval between pouring and sensitizing the plate. As a result, youmay find in your practice that the traditional amount of ether is a necessity.There is some anecdotal evidence that the substitution of denatured alcohols for eithergrain alcohol or ether may rejuvenate salted collodions or prolong the working life of themix. However, be aware that denatured alcohols are manufactured to be intentionallytoxic and any ingestion or prolonged exposure to the fumes of denatured alcohols is tobe avoided.Lea’s Landscape #7 Alternate Formula (eliminatingadditional ether)

Stock Alcoholic Bromo-Iodizing Solution:In a clean bottle capable of holding at least 125ml(~4oz) mix:190 Proof Grain Alcohol (Everclear orsimilar) 100 ml

Cadmium Bromide 1.5 gAmmonium Bromide 1.3 gCadmium Iodide 3.4 gAmmonium Iodide 2.6 gFirst, dissolve the cadmium bromide in the alcohol.Then, dissolve the ammonium bromide into thatsolution followed by the other two salts.Working strength collodion formula:In a clean bottle capable of holding at least 750ml(~24oz) mix:Alcoholic Bromo-Iodizing Solutionfrom above 100 ml

190 Proof Grain Alcohol 200 mlCollodion USP solution (~6%pyroxilene collodion) 300 ml

The working collodion should be fully ripenedand ready to use within 2-3 days.Quick-clearing collodion formulas may be found in several texts devoted to wetplate.(Consult the bibliography.)Quinn Jacobson's popular quick-clearing collodion formula is a modified version of aformula originally published in M.H. Ellis' 1856 book, "The Ambrotype & PhotographicInstructor." The following recipe makes 570ml of working collodion. It can be usedalmost immediately.Quinn Jacobson’s Quick-clearing CollodionFormulaPart A:Plain Collodion USP 240 mlDiethyl Ether 160 ml

Part B:Cadmium Bromide 3 gDistilled Water 5 mlWarming the water will facilitate the dissolution of thecadmium bromide. A glass rod may be needed tobreak apart the cadmium salt which may cake in thewater. Many wetplaters mix Part B in a test tube andcarefully employ an alcohol lamp or other heat sourceto gently warm the solution.Part C:Slowly mix Part B into Part APart D:Ammonium Iodide 4 gDistilled Water 5 mlGrain Alcohol 160 mlSlowly mix PART D into PART C and shake after eachaddition.

Silver Nitrate Sensitizing BathA sensitizing bath consisting of 9% silver nitrate with pH adjusted to make eithernegative or positive plate. The actual volume of silver nitrate solution required dependsupon the plate size being used and the capacity of the tank used for sensitizing theplates. More neutral baths (pH ~ 6) work well for negative images while positivesrequire an acidic bath (pH ~4-5). Drops of nitric or glacial acetic acid may be used toadjust the pH. Inexpensive pH monitoring paper or dedicated pH meters may be used todetermine solution pH.Once prepared, the specific gravity of the bath should be measured with a hydrometerand the initial value recorded. A brewing or aquarium hydrometer is accurate enough forthis measurement. As the bath is used and the silver removed during sensitization ofplates, additional silver nitrate should be added to replenish the bath and bring it to itsinitial value.The silver bath should be slightly iodized by letting a coated salted collodion plate sit in itovernight before the initial use of the bath.

Note that silver nitrate is corrosive and may cause blindness if splashed into eyes.Nitric and glacial acetic acids are also corrosive with caustic irritating fumes.Use these chemicals only with proper personal protection equipment and adequateventilation, and familiarize yourself with the MSDS information before attempting touse these chemicals.

Silver Nitrate Sensitizing BathSilver Nitrate 90 gDistilled Water 1000 mlGlacial Acetic Acid as neededDissolve the silver nitrate in the water andcarefully add drops of nitric or glacial acetic acidto bring the pH into the desired range for eithercollodion negatives (pH~6) or positives(pH~4-5). Use extreme care when adding theseacids to the silver nitrate solution. These acidsare extremely corrosive and inhaling their fumesmay cause permanent pulmonary damage.Finally, iodize the bath slightly by letting acollodion plate sit in the silver nitrate solutionovernight. This procedure saturates the bath

with silver iodide and prevents the dissolution ofthat salt from the surface of subsequent plateswhere it forms during the sensitization process.Check the initial specific gravity of the solution using a hydrometer. Most inexpensivehydrometers used in brewing or aquarium applications will work. You don’t need topurchase an expensive laboratory hydrometer. Just be sure the hydrometermeasurement range will incorporate values around 1.07 which is a fairly standardmeasurement for the sensitizing bath. Record the initial specific gravity level of the silverbath. (I mark the hydrometer scale directly). The bath may be replenished using a 30%silver nitrate solutions or by adding crystalline silver nitrate as needed.

Ferrous Sulfate Developer FormulasPositive Developer for Ambrotypes,Aluminotypes, and TintypesFerrous Sulfate 16 gDistilled Water 400 mlGlacial Acetic Acid 24 ml190 Proof Grain Alcohol 16 mlFilter the solution before use.Development should be timed to about 15 seconds and ended before shadow detailsbecome present. In hot conditions, the activity of the developer may be reduced andchemical fogging controlled by several means. These include dilution of the developerwith additional water, reduction in the amount of ferrous sulfate, increasing the aceticacid content, or use of an organic restrainer such as sugar in the formula.Sugar Developer VariationFerrous Sulfate 15 gDistilled Water 355 mlWhite Table Sugar 20 gGlacial Acetic Acid 20 ml190 Proof Grain Alcohol 20 mlFilter the solution before use.For negatives, a weaker developer is used for an extended time, generally about 90seconds. Less ferrous sulfate and more acetic acid is used.Negative Developer FormulaFerrous Sulfate 9 gDistilled Water 355 mlGlacial Acetic Acid 28 ml190 Proof Grain Alcohol 18 mlFilter the solution before use.In case of any unevenness of flow of the developer over the plate, a greater addition ofalcohol will help the solution flow better. (Some workers exploit this fact and use lessdeveloper to increase development streaks and other artifacts.)Adding small amounts of potassium nitrate or silver nitrate will help brighten positiveplates and produce a more neutral color. A few drops of silver from the sensitizing bathwill also help produce a brighter plate. Many workers also save the used developer andmix it up to 50% with fresh developer to obtain similar results.Filtering both fresh and used developers helps prevent small artifacts known as “comets”on the collodion plate. A cotton ball or two placed in the neck of a funnel makes a filtersufficient for this purpose. Silver nitrate solutions should also be filtered after daily useemploying a dedicated funnel and fresh cotton to prevent contamination.

Fixer FormulaFixer for Wetplate Photography

Sodium Thiosulfate 200 gCool water 1000 mlAdd the sodium thiosulfate crystals slowly to the waterand stir until dissolved completely.Plates are fixed for twice the time they take to clear or fully reverse in the case ofpositive images. Do not overfix plates. Areas of collodion along the pour-off corner maybe thicker and impervious to the fixing action, but otherwise the unexposed opaquebluish collodion film should clear before the plate is removed from the bath.

Glass CleanerGlass CleanerWhiting 50 gDistilled Water 50 ml190 Proof Grain Alcohol 10 mlMix the contents together in a clean condiment squeeze bottle by shaking. The whitingwill settle out so be sure to shake vigorously before use. Apply a small puddle to thecenter of the glass plate and thoroughly clean the surface by rubbing with a soft cloth orpaper towel. (I prefer to use PEC Pads due to their durability when wet.) Be sure topolish the cleaned plate with a lintless cloth and remove any powdered whiting that mayremain on the plate including the edges. Whiting is powdered calcium carbonate and theinadvertent introduction of this chemical into the silver sensitizing bath will raise the pHand cause problems.

Sandarac & Lavender VarnishSandarac & Lavender Varnish190 Proof Grain Alcohol 470 mlGum Sandarac 65 gOil of Lavender 50 mlIn a lidded canning jar, dissolve the gum sandarac crystals in the alcohol by periodicallyshaking the bottle. It may take several days to completely dissolve the sandarac.Grinding the sandarac crystals to a smaller size using a mortar and pestle will speed thedissolution. Filter to remove debris. Add the oil of lavender to the filtered sandaracsolution and mix until uniform. Decant the varnish into smaller stoppered bottles.To use, slightly warm the varnish bottle in a water bath while gently heating the back ofthe plate over a paraffin lamp. Metal plates will warm rapidly while glass plates will takelonger. Don’t try to rush with glass because a sudden temperature shock may crack theglass.Remove the plate from the proximity of the lamp and then flow the varnish smoothlyover the plate as if making a collodion pour. Let the plate rest horizontally for severalseconds but not for too long since the alcohol in the varnish may begin to dissolve thecollodion film. After several seconds, tip the plate vertically and from one corner, drainthe excess back into a separate collection bottle. Filter the varnish again before reuse.Warm the back of the varnished plate over the lamp in order to evaporate the alcoholsolvent and set the varnish. Be careful to warm the plate slowly and avoid ignition ofthe alcohol coming off the surface. The varnish will take several hours to dry completelyso keep the plate away from dust during this time.

Links, Resources, and BibliographyThis article has provided a very brief introduction to the wetplate collodion process. Ithas only scratched the surface. Much more information is available in various manualsand available workshops. I highly recommend reading several texts on the process aswell as attending a workshop before attempting to work the process.Information on building darkboxes, preparing genuine ferrotype plates, making collodionnegatives for albumen printing, remedying problematic baths or solutions, and general

tips and tales can be discovered in these resources. You will find the chemistry can beadapted for different conditions and effects, other tricks of the trade, and a wealth ofinformation on troubleshooting this somewhat finicky process is available if youinvestigate the following resources.

Gallery of Wetplate Photographsby Joseph Smigiel(Be forewarned that the gallery contains photographs of nude figures.)

WorkshopsJohn CofferMichael Mazzeo at Peter’s Valley Craft CenterFrance Scully and Mark OstermanNorthlight Photographic WorkshopsCenter For Alternative and Historic ProcessesWill DunniwayKerik Kouklis

Manuals, Articles, and TextsFrederick Scott Archer, Inventor of the Wet Collodion ProcessThe Doer’s Guide to Wetplate Photography, DVD and Manual, by John CofferComing Into Focus, chapter on wetplate, by Scully and OstermanThe Wet-Plate Process, A Working Guide, by Scully & OstermanWet Collodion Photography, A Short Manual, by George BerkhoferThe Contemporary Wetplate Collodion Experience, by Quinn JacobsonThe Silver Sunbeam, by John Towler, MDA Popular Treatise on Photography, by Désiré van Monckhoven (online)A Manual of Photography, by Mathew Carey LeaThe Albumen and Salted Paper Book, by James M. Reilly (online)Bill Jay's Essays, including “Dangers in the Dark”, “Move a Muscle and I'll Blow YourBrains Out”

and “The Black Art”How a Woman Makes Landscape Photographs by Eliza W. Withington, 1876 (online)

Internet ResourcesThe Wetplate Collodion ForumThe Civil War Reenactor's Collodion Photography Discussion ForumFlickr Wetplate Photography Group Image PoolDisactis (A French Daguerreotype and Wetplate Site)

Wetplate PhotographersJody AkeAllan BarnesRobert BensonStephen BerkmanMelitte BuchmanQuinn JacobsonLuther GerlachRobb KendrickKerik KouklisMatt LarkinSally MannRobert MaxwellMichael MazzeoKen Merfeld

Eric MertensMark OstermanDavid PriftiFrance ScullyKeilly Anderson-StaleyJoni SternbachEllen Susan

Reenactor PhotographersJohn CofferWill DunniwaySteve IngramSeán MacKennaChristopher MorganWayne L. PierceRobert Szabo

Chemistry SuppliesArtcraft ChemicalsBostick and SullivanChemsavers.comClarkson LabsMavidon Medical SuppliesPhotographer's Formulary

Equipment & Camera ConversionsWayne Pierce, The Company PhotographerThe Star Camera CompanySteve Silipigni/Black Art WoodcraftHow to Adapt a Film Holder to Wetplate

Safety LinksCadmium Bromide MSDSCadmium Iodide MSDSCollodion USP MSDSEther HazardsEther StorageEthyl Ether MSDSNitrocellulose (guncotton, pyroxiline) InformationPotassium Cyanide MSDSSilver Nitrate MSDSUS Dept. of Energy Office of Health, Safety, and Security article onManagement of Time Sensitive Chemicals

THE CHEMICALS USED IN THIS PROCESS ARE EXTREMELY HAZARDOUSAND ANYONE CONSIDERING WORKING IN THIS PROCESS SHOULDINVESTIGATE THE MATERIAL SAFETY DATA SHEETS FOR EACH CHEMICALAND BE FAMILIAR AND COMFORTABLE WITH THE PROPER HANDLING OFTHESE MATERIALS TO MINIMIZE ANY POTENTIAL HAZARDS.

THIS ARTICLE IS PROVIDED FOR GENERAL EDUCATIONAL PURPOSES ANDIS NOT INTENDED TO BE ENDORSEMENT OF THE USE OF THE CHEMICALSBY UNTRAINED INDIVIDUALS.

AGAIN, THE AUTHOR AND PUBLISHER OF THIS ARTICLE ACCEPT NO

RESPONSIBILITY NOR LIABILITY RESULTING FROM THE IMPROPER USE OFTHESE CHEMICALS BY OTHER INDIVIDUALS.

© 2008 by Joseph P. SmigielNo part of this article may be reproduced without permission of the author.

Thanks to Bill Schwab for providing several location photographs used in this article.