Lenticular Interlacer
Every lens on the sheet has to cover a complete set of frames, and the pitch your supplier prints on the box is a rounded figure rather than what you actually received. This page interlaces at the sub-lens level, keeps a fractional pitch instead of rounding it, and prints a calibration sheet so you can measure the material in front of you.
✦Only have one image or a layered PSD? Start in IMGTO3D to create depth views first.Expected view sequence
A clear angle-by-angle confirmation of the frames you intend the material to reveal.
Print budget
Release checklist
Frame sequenceAdd 3 more view(s).
Material pitchNominal pitch only — run a calibration sheet first.
Resolution budgetResolution will be assessed after frames are added.
Why every lens needs the whole set of frames
A lenticular sheet is a row of narrow cylindrical lenses, and each one acts as its own tiny viewer. The lens gathers the strip of print directly beneath it and sends light from different parts of that strip out at different angles, so the whole set of frames has to be packed underneath every single lens. At 720 DPI on a 60 LPI sheet each lens covers exactly twelve pixels, which for a two-frame flip means six pixels of frame one followed by six of frame two, repeating for the length of the card.
The tempting shortcut is to give one lens entirely to frame one, the next entirely to frame two, and so on. It produces a striped image that looks plausible on screen, and the repeat period quietly becomes twice the lens pitch — so under the lens there is nothing to switch between, and the card shows coarse banding instead of a flip. The check panel above reports how many distinct frames fall inside one lens for exactly this reason: it should always equal your frame count.
Fractional pitch, and why rounding ruins the far edge
Pixels per lens rarely comes out whole. Printing at 720 DPI onto a 50 LPI sheet gives 14.4 pixels per lens, and rounding that to 14 looks harmless until you count along the card. Each lens then starts 0.4 pixels early, the error accumulates, and by the two-hundredth lens the stripes sit eighty pixels away from where the lenses actually are — around five and a half lens widths, so the image has long since drifted into the wrong frame. This page tracks the boundary as a fractional value so the last lens on the sheet lands where it should.
Measuring the sheet you actually have
Manufacturers state a rounded pitch and the true figure varies from batch to batch. Because interlacing has to match the material rather than the label, the calibration sheet prints a series of bands at slightly different pitches. Lay the lens over the print, view it from the distance the finished card will be seen at, and tilt it: most bands will ripple as waves travel along them, but one will change colour all at once along its whole length. The figure beside that band is your real pitch. Work in steps of 0.1 first, then reprint around the winner in steps of 0.01. The test only holds for one combination of lens, printer, paper and driver settings, so repeat it when any of those change.
What resolution buys you
The number that matters is pixels per lens divided by frame count. Below two the frames cannot be separated at all; below three there is visible bleed between them; above five the separation is comfortable. Printing at 300 DPI onto a 75 LPI sheet with three frames leaves 1.33 pixels per frame, which no amount of clever interlacing can rescue — the fix is a coarser sheet, fewer frames, or a device that puts down more dots per inch.
Questions
Which way should the lenses run?
Ribs running top to bottom change as you turn the card left and right, which suits flips and depth. Ribs running left to right change as you tilt it up and down, which is often used for signage viewed while walking past. Match the setting here to the sheet in your hand — run a fingernail across the ribs to feel which way they go.
My flip runs backwards. What went wrong?
Nothing structural. The lens can invert the viewing order depending on how the sheet sits. Tick Reverse frame order and print again.
How do I line up the print with the lens?
The calibration sheet prints a fine line across the top, perpendicular to the bands. With the lens laid over it, that line looks continuous when the two are square to each other and broken when they are skewed. Get the line clean before judging the bands.
What resolution should I use?
Triaxes suggest 720 PPI for Epson desktop printers and 600 for Canon and most others. DP Lenticular put the floor for inkjet proofing at 1440 PPI, and plate setters at 2400 DPI or more. Higher output resolution is what lets you use a finer sheet or more frames.
Can I do a proper 3D depth effect with three frames?
Only a shallow one. Convincing depth normally needs ten to twenty views, which is beyond what a browser page can interlace comfortably and beyond what most desktop printers can resolve. Three frames give a gentle sense of layering; for real depth work you want dedicated software and a plate setter.
Should I print the test on the lens or on paper?
On the same paper and with the same driver settings you will use for the real job, then lay the lens on top. The pitch you measure is specific to that whole combination, so testing on different paper gives you a number that does not apply.