Now that you have found the pitch of the lens you need to know how many frames or images to interlace. Once again, for the sake of our printer’s precision, we will use 720 Dots-Per-Inch for the resolution of the output device. We’ll divide that by the visual pitch of the lens: 75.48 Lenticules-Per-Inch. 720 / 75.48 = 9.5389507
This means we can fit 9.5389507 dots under the width of a single lenticule. Unfortunately we cannot print .5389507 of a dot. Therefore we will round our answer off to the nearest whole dot. We will be using 10 frames for interlacing.
We are creating a 2-image flip action. We’ll designate them image “A” and image “B”. Open your interlacing software and add the images in this order: AAAAABBBBB
Because we have five “instances” of each image, we have achieved the 10 frames needed for interlacing. Next we set the physical size of the finished print
Turn on the flash bars or alignment bars to ¼ inch on all 4 sides, these will help to align the lens to the finished print. Set the LPI to the visual pitch determined earlier. In our case this was 75.48. Set the interlace direction to “horizontal” and turn off “resample” if possible. Process and save the interlaced file to your computer.
The interlaced image should be set to 754.8 Pixels-Per-Inch. This was determined by multiplying the visual pitch used to interlace the file, 75.48, by the number of frames interlaced together, 10. As mentioned before, the printer we are using will give us better results at 720DPI.
Open the interlaced file with your image editing software. Check the PPI to make sure it is 754.8. If it isn’t, change it to 754.8 but do not resample the image. This will change the physical size somewhat, but hopefully not drastically.
Now change the PPI to 720 and this time resample the image. Once again, we will be using “Bicubic” as the interpolation method. This will not change the physical size of the image. It is reinterpreting the image that would interlace the best for the lens we are using to a format that will print better on our printer. Save this file as a copy, in case you need to refer back to the original.
Once again, rotate the image so that the interlacing runs vertically. Set the printer to 1440DPI and print the image.
Tape the print at the corners to a nice flat surface. Apply the optically clear adhesive to the print. Be very careful not to introduce any air bubbles or fold lines.
Align the lenticular sheet over the print. Use the flash bars around edge of the image to help you align the lens. When the lens is aligned correctly, you will see an even and uniform black frame around the image.
While holding the lens in place tape the edge of the lens down to form a temporary hinge. Tilt up the lens slowly, be very careful not to shift it out of alignment. Peel the film backing off the adhesive and slowly lay down the lens onto the adhesive. Using a roller or laminator should help get a smooth, bubble-free result.
Learning to laminate lenticular prints to lens requires some practice. Be prepared to print a number of images, and if possible have some extra lens and adhesive on hand. With some patience and some trial and error you will produce a great lenticular piece.
Banding: if the image appears to be flipping in bands or stripes, rather than the entire image at once, try reprinting the image with a different DPI setting for your printer. Often a higher DPI (and sometimes lower DPI) will reduce this problem.
Diagonal Sweep: if the image appears to sweep at an angle across the image rather than a fairly quick flip from one image to another, it probably means the lens is not squarely aligned to the print.
Horizontal Sweep: if the image appears to sweep across rather than flip between images, it means that the pitch is slightly off. Put the image down and look at it back in forth while moving your head. If the sweeping appears to move in the opposite direction of your head it means that the pitch number is too large and you should try interlacing to a smaller LPI. If the sweep appears to move with your head, it means that the pitch number is too small and you should try interlacing to a larger LPI.
Hopefully this will get you started on creating your first lenticular print.
Good luck!