17Packaging India June - July, 2011

IntroductionThe marketing impact of a product can be greatly improved by using 3D or moving objects. In a survey conducted by a reputed agency, people preferred 3D ads almost 2.5 times more than its 2D ads. In the same survey it was also found that people felt that the 3D ads looked better almost twice, as compared to 2D ads.

Lenticular printing technology has come in very handy in making the 3D advertisement possible at the Point of Purchase (POP), thus assisting in the increased sales at an affordable advertising cost. The advances in the lenticular printing and material technology have resulted in the evolution of practical and profitable advertisement applications. Marketing impact on the consumers mind is greatly improved by using the Lenticular printing technology. Though the advanced countries have adopted this technology for several years for

maximisation of marketing, in India we are still at a nascent stage and thus, we have great potential of tapping this market in the near future.

In this article, a brief of the lenticular printing technology is discussed with relevance to its application and usage.

Lenticular TechnologyOptical lenticular sheets are fine linear arrays of convex lenses with specific optical viewing

Bhupendra SinghGeneral Manager Technical (Material Science Setctor, Polymers Films Division)A. D. Plast Pvt. Ltd.Navi Mumbai

The lenticular print allows the

consumers to halt, move from

side to side to watch the display

thus ensuring that the consumer

spends more time with the product

advertising for better impact.

18 Packaging India June - July, 2011

characteristics commonly known as Lenticular. The lenticular lenses are made from special pieces of transparent plastic sheets with numerous lines on one side of the surface is as shown in Figure 1.

The lenticular lenses are defined by their number of the lenses per linear inch on the lenticular sheet for example 60 lenses per inch (LPI) means 60 lines per inch or 60 lens per inch i.e. one inch of lenticular sheet will have 60 lines (lens) on it. Lenticular sheets are available from 10 to 200 LPI for various commercial applications.

Commercial quality optical lenticular sheets are generally produced by extrusion of optical quality polymer such as APET, PETG, PMMA, PS, PC or PVC onto cylindrical engraved mandrel. This technique is very popular due to its cost efficient and large volume production. Lenticular material can be provided as individual cut sheet or in web rolls of defined width. Lenticular sheets made from PET are becoming very popular in commercial printing applications.

Lenticular PrintingLenticular printing or 3D stereoscopic printing is a technology which uses a lenticular plastic to produce images with an illusion of depth or the images have the ability to change or move as the image is viewed from varied angles. 3D Lenticular Printing can be carried out by two different methods. One is called direct lenticular printing; in this case the image is printed on the plain side of the lenticular sheets whose thickness must be less than 1mm, which is suitable for big batch manufacture. The other one is called lenticular lamination, where the image is printed on the paper at first, and then the paper is laminated on the plain side of the lenticular sheets or boards, which is suitable for smaller run.

InterlacingInterlacing is the key to the lenticular printing technology. Interlacing is a process of stripping a sequence of images for creating the effects. For

The quality of the lenticular sheet is dependent on the clarity of the sheet which in turn depends on the type of material used for making the sheets and also the process controls.

example, for a flip effect of 2 images, the first band is a strip from image 1, the second from image 2, and the third from image 1 and so on. It is mostly a mathematical formula that slices images to the right width and arranges them accordingly. The software then saves the interlaced image in a file which is ready for printing. An image print is produced whose characteristics represent a map of the interlaced images and which includes one or more desired visual effects.

The interlaced image is printed directly on the back of the lenticular piece of plastic or it is printed on paper which is then laminated with lenticular plastic sheet. The lenticular lens isolates and amplifies the interlaced image underneath it in such a way that only one original image at a time is seen by the viewer. The image changes with the change in the angle of observation. When the lenses are placed vertically, each eye sees a different image and thus creates an illusion of a 3D image. Lenticular images are very attractive and 3D effects can be produced with amazing effects.

Applications of Lenticular PrintingLenticular printing is finding innovative and attractive applications in various fields such as advertising and packaging. Few applications of lenticular printing are listed below:l Cards l Calendarsl Coastersl Electrostatic stickers l ID cardsl Magnets l Mouse padsl Playing cardsl Scratch- off cardsl Vinyl stickersl Trading cardsl Video / CD covers

Adhesive layer

T

Protective filmFigure 1: Lenticular lens sheet.

Figure 2: Interlaced image.

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l Postcardsl In-store signsl Membership cardsl Loyalty cardsl Frequency cardsl Key ringsl Stickersl Mobile coversl Postersl Menu boardsl Brochuresl Magazine inserts l Comic books l Mini cataloguesl Pressure sensitive and self adhesive

labels etc.

Lenticular EffectsVarious effects are possible with lenticular technology such as direct flip, zoom, morph, animation and 3D. Based on the effect required, the artworkneeds to be modified to obtain desired effects.

Direct Flip This process is one of the most basic forms of lenticular effects. It works great for illustrating before and after effects. Flip is a good way to deliver multiple messages within the same space.

This process involves 2 to 3 different images which switch back and forth, the animation may be

up / down movement or side / side movement. Up / down movement is crispest switch since both the eyes are on the same plane when viewing. Flip imagery is great for associating a product or brand with an appropriate message. For example, a photo that illustrates a product feature or lifestyle could then change to company logo.

Zoom EffectA zoom effect begins with a smaller image and transforms it into a large version of the image. Zoom effects is a great way of communicating a message. This process is similar to using a zoom lens on a camera. Motion blur techniques can be incorporated to enhance the effect and increase focus on the central image. Zoom effect is a great way to highlight a product or logo within a photograph or illustration.

Before

After flip

Before After Zoom

Morph EffectIn this effect one image is a gradually transformed into another different image using computer animation. Better results are obtained if both the images used are of similar shape and size.

Morphing Sequence

Animation / MovementThis type of effect is generated by use of several sequential images which differ slightly from one image to the next one. Both the eyes tend to observe the same image, but small movements of the observer and the printed object can cause a transition to the next image in the sequence. Using around 30 images, it is possible to create a full animation video that can last about one full second.

22 Packaging India June - July, 2011

3D EffectEach eye sees a different image. Due to the angle the images are printed, creates a 3D effect on all or part of the image. The 3D effect requires only very small change in the viewing angle to bring about change in the observed image.

Selection of LensesSelection of Lenticular Sheets Based on LPIThin lenticular lenses are suitable for small handheld pictures; lenses above 60 LPI are considered to be thin lenses. These lenses are preferred for close-up applications where the application involves short viewing distances. Thin lenses find major applications in packaging, postcards, greeting

cards, business cards, puzzles, cups and various promotional items (Table1).

Thick lenticular lenses range from 10-60 LPI; are sturdy and perfect for large outdoor and indoor advertising applications. Thick lenses are more suitable for printing wide format applications and find use in airport, tradeshows, malls, bus shelters, train displays etc.

Selection of Lenticular Lenses Based on Printing TechniqueThe selection of the printing methods based on various lenticular sizes is as given in Table 2. For voluminous jobs it is preferable to use offset printing.

Selection of Lenses Based on Viewing DistanceIf the viewing distance from the object is known then it becomes easy to narrow down the selection of the lenticular lenses. The relationship between the viewing distance and the LPI of the lenticular sheets is given in Table 3.

Selection of AngleThe angle of lenticules is important when selecting the lens. For a good 3D effect, a narrow-angle lenticular lens with a viewing angle between 15-44 degrees works better. While for a good animation effect a wide angle lenticular lens having a viewing angle between 44 to 65 degree works better.

Lenticular sheets are available in thickness range

Table 1: General Applications of Lenticular Sheets Based on LPI and Thickness

Sheet Thickness and LPI Application

20 mil – 60 LPI Flip / animation lens and large format

33 mil – 40 LPI Large format general

18 mil – 75 LPI General lens (hand held medium – large and poster)

14 mil – 100 LPI General lens (hand held small medium)

23 mil – 100 LPI 3D speciality lens

10 mil – 150 LPI Labels

Table 2: Selection of Printing Process Based on Lenticular Lens SizePrint Process / LPI 10 15 20 30 40 50 75 85 100 140 200

Large Format Inkjet x x x x x x

Offset x x x x x

Flexography x x x

Table 3: Relationship between the Viewing Distance and LPI of the Lenticular Sheets

Distance / LPI 10 15 20 30 40 50 75 85 100 140 200

6”-12” x x x x x

1-2 feet x x x x x

2-6 feet x x x x

6-15 feet x x x x

15-30 feet x x x

> 30 feet x x

Various effects are possible with lenticular technology such as direct flip, zoom, morph, animation and 3D.

23Packaging India June - July, 2011

from 0.008 to 0.385 inch. Standard sheets are available in various sizes; the most commonly used sheet for offset printing is 20” x 28” to 28” x 40”. Lenticular material is also available in continuous roll form which is used for the web printing purposes.

The quality of the lenticular sheet is dependent on the clarity of the sheet which in turn depends on the type of material used for making the sheets and also the process controls.

Choosing the Correct Lens OrientationHorizontal Lens DirectionThe horizontal lens direction is the best choice for motion images and for flip images.

Vertical Lens DirectionIt is advisable not to use the horizontal lens direction for ‘walk-by’ displays or posters; for this applications vertical lens direction is preferred. Also 3D works best with the vertical lens direction.

Conclusions Lenticular is a unique display medium which offers fascinating effects to flat prints; it increases the visual awareness of the product and services. Consumers are fascinated by the lenticular effects when they walk past the lenticular print. The lenticular print allows the consumers to halt, move from side to side to watch the display thus ensuring that the consumer spends more time with the product advertising for better impact.

Lenticular Printing technology will bring a revolution in the marketing and brand promotion for the products. As the maturity in the market increases more and more people will try to explore this mode of advertisement for better effect and brand buildup.Horizontal lens direction. Vertical lens direction.

The advances in the lenticular printing and material technology have resulted in the evolution of practical and profitable advertisement applications.

TRAINING AND EDUCATIONTo meet the growing demand from industrial units in both the organised and unorganised sectors for qualified technical manpower, the Institute introduced the 2 year programme leading to a Post-graduate Diploma in Packaging, in 1985. The course is designed to equip candidates with all the facets of packaging activity. Over the years, a large number of students have been graduated and have found excellent placements in industrial units.

Other courses being offered by the Institute include the Distance Education Programme – Correspondence Course since 1996, recognised by the World Packaging Organisation and accredited by the Asian Packaging Federation. The 18-month course designed primarily for working professionals, is open to industry personnel and to students in India, the Asia-Pacific region and other countries.

A 3-month Certificate Course in Packaging introduced in 1968 is conducted at the Head Office and also at the Regional Centres. Admissions are on a first-come-first-served basis. The course is also open to overseas participants deputed by their governments under various schemes.

Short training programmes, seminars and conferences organised by the Head Office as well as the Regional Centres are conducted throughout the year in various parts of the country.

Contact for details:

Indian Institute of Packaging (Mumbai • Chennai • New Delhi • Kolkata • Hyderabad)

E-2, MIDC Area, Andheri (E), Mumbai 400 093 l E-mail: iip@iip-in.com l Website: http://www.iip-in.com

Offers a wide range of services to the industry: