For this tutorial we’ll keep things as simple as possible, so we’re going to do a simple flip from one image to another. This tutorial is intended specifically for use with desktop inkjet printers. Designing lenticular for press is a little different, but this method will allow you to create action proofs far more cost-efficiently than on a proofer.
It will also be very helpful to have a laminating device, but if you’re careful and have good eye-hand coordination you may be able to do without it.
First we need to create a pitch test. This will allow us to determine the exact pitch of the lens based on the intended viewing distance of the finished piece. A lenticular print will have a different pitch depending on if it’s intended to be held at arm’s length, like a post card, or if it’s meant to be viewed from several feet away like a poster.
Your interlacing software will create a pitch test to your specifications. Follow the instructions for your software to create the pitch test (sometimes referred to as a pitch checker form), We’ll use 75.5 as the center pitch for our test. Flip Signs software gives us resolution choices of 600, 1200, or 2400DPI. We’ll use 1200DPI. Save the pitch test file to your computer.
Our pitch test is 1200DPI, but we’ll target 720DPI for our printer because it prints most precisely in multiples of 720DPI. Precision is important because we do not want to introduce any errors such as “banding”. Therefore we need to resize our pitch test. Open the file in your image editing software. Change it to a grayscale image and resample it to 720DPI. You may want to experiment with different interpolation methods when you resample your images. For this example we will be using “Bicubic” as the interpolation method.
Before printing, rotate the image so that the interlacing runs vertically. This is necessary because the horizontal motion of the print head of the printer is much more precise than the vertical motion of feeding the paper through the printer. We need to be as precise as possible to keep the correct information lined up under the lenticule.
Save the file to your computer, and print it on 8.5” x 11” photo quality paper, with the orientation set to “Portrait”.
Align the lenticular lens over your print. If you have extra lens, you can laminate the lens to the print. Orient the print and lens so that the lenticules run vertically. Stand away from the pitch test at the typical viewing distance you intend for the finished piece. Now move your head side to side and watch the pitch test.
You should notice that the higher LPI bars appear to move in the same direction you are, and the lower LPI bars appear to be moving in the opposite direction. These opposing movements should appear to come together where the visual pitch will be. The ideal pitch bar shouldn’t appear to move much at all, but instead it appears to flip from a solid black bar to a solid white bar. Where the quickest change happens is your visual pitch. Make a note of the LPI of the pitch bar you have chosen as the best. Our example was 75.48LPI.
Whew! It's a little technical, but it's critical to get the best pitch possible for your lens and your application. Take your time. When you're ready, continue on to page 2.