You will see a spec in your quote calling out the “LPI” and thickness of the lenticular material. That may not be familiar to you— most people, even those who have spent a lifetime in printing, are unfamiliar with it. It’s not something you will need to choose, and we are here to make sure your project has the very best lens for the job. But if you’d like to learn a little more about what LPI is and how it affects your image, read on.
LPI stands for “Lenses Per Inch.” Sometimes it gets referred to as “Lines Per Inch,” as the lenses are in fact the lines that form the lens. When you run your fingernail across the lens, you feel (and hear) the ridges that run in one direction. Those lines are the lenses that separate the underlying image, hiding one frame from view. As you change your angle of view, the lenses hide the next frame and reveal the previously hidden one. That is, in a nutshell, how lenticular creates an animation. Tilt the card, or walk by the print, and you see one image change to another.
So now that we know what the lenses do, let’s explore what the LPI spec is all about. If the material has more lenses per inch, each line/lens is of course thinner. Lenticular lenses typically run from about 10 LPI up to about 100 LPI. Lower LPI numbers mean thicker lines. The upside of thinner lenses is that those lines running through the image don’t pixelate or obscure it as much. The smaller the detail in the image, the more it is subject to being obscured by a thick lens (low LPI).
The upside of a low LPI lens is that it does a better job of hiding the dot in the print, which translates directly to a stronger effect. The hidden image is better shielded by the thicker lines. If the line is too thin, the hidden image peeks through, and you never get true distinction from one frame to the next.
Simply put: Low LPI give you a better effect. High LPI gives you a clearer image.
So how do we choose the right lens for the job? Generally, it’s best to use the lowest LPI that won’t obscure the image. That depends on how large the image is and how far away it will be viewed from. Using a 20 LPI lens on a postcard would not look good — the lenses are so thick that most detail would appear choppy and obscured. But on a 48″ x 72″ panel, that’s not an issue. And if we use a 75 LPI lens on a 48″ x 72″ panel, those thin lenses won’t adequately hide the dot, and the effect will be weak.
Most prints smaller than about 18″ x 28″ will use a 75–100 LPI lens. Most prints larger than that will use a 10–40 LPI lens.
We’re here to make sure your project has the best lens for the job. We rarely ask clients to get involved in that choice — but rest assured that we have all of the best lenses available and will make sure that LPI, and every other aspect of your project, is specified to maximize quality and deliver the best lenticular print possible.
