impregnated paper.pps

Replacing varnishes on architectural drawings on impregnated paper

Rita UdinaPaper & book restorer. Barcelona (SPAIN)

Symposium Technical drawings and their Reproductions The Hague 6-7 October 2014

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Shellac Transparency

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Shellac Oxidation (yellowing)

Oxidation Fragility Cuts

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Bends Cuts …. Scotch tape

Fragility

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Cracks, tears

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Goals to achieve with the restoration treatment:

• Stop oxidation, or even revert some of its consequent acidification.

• Retrieve lost flexibility.More flexible Less consolidation (layers) needed

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Being aware of:• Importance of transparency

main purpose from the addition of shellac).

• Strict maintenance of scale(plans/maps).

Less important:

• YellowingConsequence with no damage by itself.

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Shellac

• Transparency,• Oxidation• Brittleness

Other varnish

• Transparency,• RedOx stable• Flexibility

Maintenance of scale:Avoid aqueous treatments?

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Treatment case 1

• Impregnated laid paper

• 1918

• Ink, watercolour.

• Several fragments (40 x 60 cm aprox.)

• 90 µ thick

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Treatment case 1

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Treatment case 1. After varnish removal (ethanol)

Loss of transparency (watercolour seen only on the back)

Flattening,Adding missing areas

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Washi paper + paste

Lining

Apply varnish

Watercolour shows again Paraloid B72, 50gr/L

Tainted washi paper+ Beva Film(+ Klucel )

Treatment case 1

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Treatment case 1

cracks

tears

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Results

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Good, though not excellent when lining.

Intense colour tone OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH=5,0 pH=7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Good, though not excellent when lining.

Intense colour tone OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH=5,0 pH=7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

TRANSPARENCY

Good though limited when lining.

Slightlier opaque

Improvement suggested

Use of Gampi paper instead (more homogeneous appearance, wouldn’t intefer that much on transparency)

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Good, though not excellent when lining.

Intense colour tone

OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH=5,0 pH=7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Good, though not excellent when lining.

Intense colour tone

OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH=5,0 pH=7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Not bad, though not excellent when lining.

Intense colour tone

OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH=5,0 pH=7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Not bad, though not excellent when lining.

Intense colour tone

OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH = 5,0 pH = 7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Good, though not excellent when lining.

Intense colour tone

OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH = 5,0 pH = 7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Characteristics Before After

Innocuous

Transparency Good, though not excellent when lining.

Intense colour tone

OK

ScaleGuaranteed even with aqueous treatments

Detrim

ental

Ongoing oxidationDue to shellac

--- Significantly reduced

Acidity pH = 5,0 pH = 7,0Significantly reduced when aqueous tretament is possible

BrittlenessUnsafe

handlingSafe

handlingExcellent improvement

Yellowing A lot Still a lot Insignificant improvement

Diminishing yellowing depends on varnish remnants and oxidation degree

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Other aspects

Applicability Presence of stamps, scotch tape, techniques (ink, watercolur, graphite), papers (diferent thicks…).

Reversibility

Toxicity

Ethanol bath

Ethanol + Toluene bath

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Replacing varnishes on architectural drawings on impregnated paper www.ritaudina.com

Contact details:

Rita Udinainfo@ritaudina.com

Further information soon at my blog:http://ritaudina.com(subscribe by email)

Thank you!