This website has been developed to give you more insights about lenticular sheet material and the applications it can be used for. Lenticular sheets come in a variety of basic raw material, and understanding the differences will help you in making the right choice for your applications.
What is a lenticular sheet?
A lenticular plastic sheet is a translucent plastic sheet which has one smooth side (this is the side you print on) while the other side is made of “lenticules”. These are small convex lenses that allow the transformation of a 2D image into a variety of visual illusions. Each lenticule acts as a magnifying glass to enlarge and display the portion of the image below.
Characteristics of a lenticular sheet
What is the most important piece of a successful lenticular print? The lens of course! Because the material is indeed a lens, it must be as clear as possible, but still have the required quality to refract light. The material should also be as stable as possible to minimize the distortion that can occur when temperatures change, yet it needs to be flexible enough to use in printing presses and to be rolled for shipping.
When you add up all these requirements, it’s obvious that choosing the correct lenticular sheet is just as important as choosing a beautiful scene. Just as with any plastic, lenticular sheets also have a set of specifications for different uses and applications.
There are several parameters that will help you decide the type of lenticular sheet you need for your project:
- Material – lenticular sheets are usually made from one of the following materials: Acrylic (PMMA), APET, PETG, Lenstar™, Polycarbonate, Polypropylene, PVC and Polystyrene.
- Density of lenses – It is commonly expressed as LPI (Lens per Inch). Common LPIs are 40, 50, 60, 62, 75, 100, 3D-100 and 150 LPI. For inkjet printing projects, posters, POS signage or larger prints on wide format printers, 20, 40 and 50 LPI works very well. An overview of typical lenticular sheets can be found here. Flexo will require a thinner lens and a much higher pitch.
- Thickness – It is measured in µ, inch or mm and comes in a range from 0.25mm all the way to 6.3mm. The thickness has a reverse correlation with the density of LPI. The lower the LPI the thicker the lenticular sheet will be.
- Viewing Angle – Within this v-shaped viewing region, lenticular images can be seen clearly. In general, the viewing angle is a guideline to determine the type of lenticular effect. A small viewing angle makes the picture very sensitive to change in thesense that a viewer just needs to turn the head slightly and a different set of pictures will be seen. For wide angle lenses the viewer can make a relatively bigger head turn to see a different set of pictures so the change is not so sensitive. Because of this fact, narrow viewing angle lenses are good for 3D effects and wide viewing angles lenses are good for dynamic prints such as animation, flip, morph or zoom.
- Viewing Distance – The distance between you and the lenticular image is called the viewing distance. This is an important factor when choosing a lenticular sheet for your application. The number of LPI and the optimal viewing distance are inverse correlated so the higher the LPI, the shorter the optimal viewing distance will be.
- Transparency – The higher the transparency the clearer and better the visual effect. It should have a minimum transmittance rate of 85%.
- Durability and Stability – Different materials also have a different reaction to temperature and UV light. Some materials are good for indoors only and some are good for both indoors and outdoors.
- Printer/lens resolutions divisibility – For the best results, the resolution of your output device has to be compatible with the lens resolution. While HP and Canon printers have resolutions in multiples of 600 DPI (Dots Per Inch), Epson is in the 720 DPI scale. These numbers limit your choice of lenticular sheets. Simple math will show you why. Let us use Epson’s 720 and a 40 LPI lens as an example:In one inch the Epson printer can print 720 dots. Since 720 is perfectly divisible by 40, we get a whole number 18 (720 / 40 = 18), meaning that under each lenticule there should be 18 dots. This combination will give fine results. However, if a 42 LPI lenticular sheet is used, the result is not an even number, meaning there will still be 18 dots below each lenticule but the last dot will be partially on the next lenticule. Because of this the intended effect will be either ruined or less visible. To avoid these problems the file will be resampled to the physical resolution of the printer.
Recyclability and the environmental aspect should be another important factor in your decision making. Not all lenticular sheet materials are made from the same resin, and some might not be recyclable at all. Recyclability is becoming a major issue and many customers will demand this. A stable sheet will decrease the waste in offset printing.
Choosing the Right Lenticular Sheet
Last but not least!
Good Quality Control and stable production environments are very important in the lenticular business. Some suppliers buy lenticular sheets from different manufacturers, with different characteristics, making it very hard to get a stable and predictable production environment. Always having the same material, preferably from the same production batch, is crucial for lenticular printers in order to obtain a stable and high quality result.
Some interesting links:
DPLenticular: find answers to FAQ on the website of this supplier of lenticular sheet material
Lenticular Technology.com: for more detailed information about lenticular technology
Pacur: lens material manufacturer
LLPA: Lenstar Lenticular Print Award