I recently had the opportunity to work on creating some lenticular prints for a client, which turned out to be an interesting undertaking. Until recently, I didn't even know what a lenticular print was, so I thought it fitting to write a post-mortem of sorts about learning on the job and making things with your hands.

As with any commercial print job, I initially tried to find a printing company that would be able to make the product we were looking for. I won't get into job specifics here, as this post is focused on the process, rather than the product. However, the initial brief was for about 40 A5 sized lenticulars, each with a different image/animation.

Let's start at the beginning though: what exactly is a lenticular print? You might recognise the effect from movie posters, some advertising, or even on special edition Pogs or Tazos. What the viewer sees is an image that changes as they physically move around the poster or object. Similar to a holographic foil, but much simpler; the most basic effect is to have one image morph into another. Some might invoke a 3D effect by moving elements in parallax as the viewer moves, to give the image depth. These are similar to stereoscopic images that take two angles of the same picture to be combined as a 3D graphic.

It might not make a lot of sense to try and describe, but the GIF above shows the effect of one image morphing into another. The GIF uses a tween animation between two frames, which simulates how you might view the effect in reality. Imagine you're walking down a corridor at a theatre and there's a movie poster on the wall. As you approach from one side, you see an image of a man's face. While you walk down the corridor, the face begins to change and morph into that of a woman's. By the time you have passed the poster, all you see is the woman's face, but the advertisement has never moved or changed its composition. 

To understand the effect, we need to know how it is achieved, which is actually quite simple. Let's focus on a basic morph between two images (check out the examples below to follow along visually), because it's the simplest and perhaps the most effective way to understand.

The first task is to create a single interlaced image of the two frames. An interlaced image is one that is made up of alternating lines of each image, so the two images are combined, but still separate from one another. The first image below show the two frames of this examples, followed by the interlaced version, as well as close up of that interlacing:

There are multiple ways of creating an interlaced image, but thankfully some are easier than others. The tricky part is making it so that it will suit a lenticular lens and get the effect you're looking for. After all, an interlaced image on its own will not appear to morph as you walk by, it will just look blurry and abstract. To get the correct measurements, we next need to know the specifications of the lenticular lenses we will be using.

A lenticular lens is essentially a sheet of plastic that is flat on one side and bumpy on the other. The bumpy side contains the lens element as it's made from a series of convex curves that act to focus light depending on the angle of viewing. I made a highly detailed diagram *cough* to show you what I mean:

This is how the effect of two images morphing into each other is achieved. With the lenticular lens, the viewer is restricted to seeing only the part of the image that is in focus, which depends on the angle of the lens through which it is viewed. As your eye moves along the curve of the lens, the focal point shifts and replaces the first image with the second. 

These convex ridges are repeated on a small scale so that when viewing the lens from afar, your brain edits out the gaps and forms a complete image. If you view the lens up close, it becomes apparent that you are essentially looking at half an image, as every second line is edited out by the lens and your brain.

This is where we get back to the interlacing of the two frames. There are different resolutions of lenticular lenses available, which are measured in lines per inch (lpi). As you might expect, the lpi of a lens designates how many curves/lines exist within an inch on the lens. Different sizes can give different effects, but for this job we used 60lpi lenses.

The link becomes simple between the graphic and the lens, as we need to match the amount of interlacing to the lens resolution. If we create an interlaced image that follows a 60lpi resolution, we can be confident that each curve of the lens will match up with the image and give the effect we're looking for. If our resolutions didn't match, then we might get an odd effect of seeing more parts of the image than needed, distorting the result.

Remember how I said there are multiple ways to create an interlaced image? Well, the desired resolution can be fed into some equations and maths can be done, then the images made, but I'm not interested in doing maths. I'd rather stick to the creative side and find some software to figure it all out for me.

Thankfully that software has been made by some smart mathematical types, and is available for us to make use of. I tried a few different programs, with varying results and features, but eventually settled on one that was provided by the company who I ordered our blank lenses from. It's a basic program, but has all the elements needed for the outcome I was looking for.

Using the software to create the interlaced images was simple: enter the output size of the image, the resolution and orientation of the lens, make a few selections from a few options, then output to the filetype of your choice.

Then it's simply a matter of sticking the lens to the printed image, and the illusion is created! Except there's more to it than that, but for now let's look at it as we did during the project itself.

So far it's a lot of messing about with interlacing and lens resolutions, so why not just get someone else to print them and save yourself the trouble? Ultimately it comes down to cost, as most things often do for commercial projects.

As with any commercial printing, volume is what saves money at the end of the day. The more you order, the less each item costs. This is a logical outcome, as commercial printing houses use systems that are very good at repeating the same job over and over again, but require work to change from one job to another. We were after 40  unique lenticular prints, so it was always expected to be relatively expensive, but some of the quotes I received made my hair stand on end.

Essentially, the job was too small for a commercial printer to take it on. I contacted all the lenticular printing companies I could find in Australia, and even tried some in New Zealand and America for good measure. Half of those told me they weren't interested in such a small job, while the others quoted me some extremely high costs, with specific limitations. Ultimately if we wanted to get these lenticulars professionally printed, it would cost over $100 each, and all 40 had to be the same image.

Due to this expense, I also researched how I could make them myself and if it would be worth the effort. Sourcing the materials (like lenses) was a little difficult, as there were only a couple of suppliers I could find online, but the process was easy enough to discover. Eventually I was able to estimate that I could make them myself for less than $50; more than half the lowest quote I had received. There were also some initial setup costs to acquire materials, but by making them myself, I could also create 40 different images in a fraction of extra time.

The risky part was that I had never made any lenticulars before, and as I mentioned earlier, had only just discovered that they even existed. Naturally I presented this as the 'risky but cheaper' option to the client, along with the commercial quotes I had received. Making them by hand would be risky because the initial investment in the materials needed to start was too high for me to absorb if it all went wrong, so it meant the client would potentially be investing in an endeavour that may not pay off. Thankfully after some discussion, my client was willing to invest in the hand-made option, as the reward of lower costs and unique images would be highly desirable. To keep it short, I ordered all the materials we needed and began working on what would be the final product.

I began testing out different software packages for creating the interlaced images and went through a few trial periods before settling on the program I ended up using. The main differences in each program came down to interface and extra options. As with a lot of niche software, the user interfaces were all basic and simply functional. Some had bad English translations and were hard to navigate, while others only presented limited options for automation. Eventually I stuck with a program that did the job, but required a little bit of prep work.

We decided to start by making 27 lenticular prints for our initial run, which would require about 54 (27 x 2) images to get started. The final plan was to have 24 flip images (morph from one frame to another), 2 animated images (a single photo with elements moving through 3-4 frames), and 1 with a 3 frame flip (same as the 2 frame flip, but with 3).

By this stage we had decided on the final sizing of each lens, which was smaller than the blank lenses I had ordered, so it meant I would have to cut each one down to size. The blanks we had ordered were larger because we were unsure at the time what the final size would be. This ended up being a blessing, as I was able to print each interlaced image with a border of guidelines, as you can see in the example below:

Once the interlaced images were created digitally, they were printed on high resolution paper for the final product. Each blank lens comes equipped with a glue applied to the smooth side and protected by a plastic film. All that is required is to remove the film and fix the lens to the print, but the fiddly bit was aligning the lens correctly.

With a resolution of 60lpi, imagine what would happen if each curve on the lens wasn't parallel to the lines on the print. This turned out to be the most difficult part of the process, and one that would take a number of test prints to get used to. I soon learned that if the lens wasn't aligned precisely, the morph effect would shift to a banding effect. This banding would appear as multiple shifts across the image, instead of one clean morph from one frame to the other. I've tried to illustrate it below:

While I was making up some test pieces, I managed to create all manner of different effects that changed depending on the alignment of the lens to the print. Sometime it would be obvious and fairly tacky, other times it would be more subtle and less jarring. In fact, some of the misaligned testers still looked good, even though they appeared more hand-made.

This is a lesson that I learned and would like to impart to others: when you're making something by hand, it will probably look hand-made. It might seem obvious, but when I started testing out lenticulars, I was trying to make them perfect, as a machine would make them. That isn't to say that they didn't look good, but only a handful ended up perfect, while others had slight imperfections. However, these imperfections made interesting effects that were still desirable on the final pieces, so it's hard to say that they were any worse than the others.

Either way my client was happy with the progress I had shown them and I set about making the final products.

I was still worried about lining up each lens, so took a lot of time to ensure that they would be the best they could be. It was a difficult part of the process as it required lining up each lens with its associated print, then removing it to peel back the protective film and expose the glue, before replacing it to the print where it would stick fast.

The part about removing the lens to peel back the film is the scary bit. It's easy enough to line up a lens on top of its interlaced print, but removing it once it's in place undoes all the careful alignment you'd achieved. I tried many different ways of removing the film without messing up the alignment, but eventually settled on a trusty strip of masking tape fixed to one edge.

Of course, this method is far from infallible, as the lens is likely to move a little when it is lifted. I found that I had to have a little bit of faith when sticking the lens back to the print, by lifting it carefully and trying not to shift it while removing the plastic film. It's the one part of the process that relies on a bit of luck and chance, as it's impossible to know if the lens is aligned properly until it's glued firmly to the print. Thankfully after applying lenses to all 27 prints, there were only one or two that were pushing the limits of misalignment. There were many that weren't perfect, but they still looked great so I was ready to proceed.

Now that each print had a lens glued to it, each needed to be passed through a cold laminator to press each side together firmly. Laminating is a simple step as it's as easy as feeding each lens through a machine, but it really helped to remove any air from between the lens and the print. It reminds me of putting a protective covering on a mobile phone; those fiddly sheets of plastic that always end up with air bubbles that we spend ages trying to push out. 

Laminating the lenses was a simple step and signified that each lenticular print had been completed. The only thing left was to cut them down to size, as each was still larger than they needed to be.

With all the bumps, convex curves, glue, and high resolution paper, each lenticular was too thick and sturdy to trim with a knife or guillotine. Instead I found that the best way to trim their edges was with a hefty pair of scissors. The downside being that this was another chance for the hand-made process to fail. We've all tried to cut a straight line at some point, only to end up with a wonky series of hacks that all divert from each other. 

Not only is cutting a straight line in a thick plastic lens difficult, but after a few cuts my eyes lost focus, as I was trying to follow a border that could only be seen by looking through the lens. When I was done with all 27 lenticular prints, I had a blister on my thumb (from gripping the scissors) and my eyes were crossed from intently focusing on a lens-distorted line.

Nevertheless, good things come to those who persist, and soon enough I had a stack of lenticulars with some fairly straight edges. I hadn't considered it in advance, but decided that fairly straight wasn't straight enough and the edges looked a bit too sharp for comfort.

Before long I found myself sitting outside with a sand paper block, sanding back the edges. There's nothing special in the technique, but I used a fine grain sandpaper to straighten any wonky edges, and apply a slight bevel to the front and back of each piece. The bevel was minimal, but it helped soften the edge, so I followed it up by gently rounding each corner. The result were edges that looked cleaner and were no longer sharp and harsh to the touch. Unfortunately the poor sandpaper didn't last long against the combination of plastic, glue, and paper, but it provided a valiant service that finished off the project neatly.

NB: This is just a quick example I made for this post - it's not as polished as I would otherwise want it to be =)

Sanding off the edges turned out to be like putting the final polish on a piece of wood. I hadn't anticipated the need for this step, but in the end it proved worthwhile and the final pieces turned out great.

They still ended up looking handmade, but I like to think of it more as hand-crafted. Sure they're not all exactly the same around the edges, and some lenses are more precisely aligned than others, but the effect was achieved and the outcome was better than I had first anticipated. Ultimately though, my client was happy with the result, which is enough for me to be happy as well. Although, I'm personally happy with achieving a great result from a technique and process I had to learn on the fly.

So was it worth it in the end? No surprises here that I think it was definitely worth it. For a fraction of the cost of a commercial printer we were able to produce a bespoke hand-crafted product that satisfied the brief.

One day, if the opportunity arises, I'd like to go through a professional printer to have some lenticular prints made, just to see what the difference would be. Of course, I expect a commercially made product to be of higher quality, but I wonder if it would have the same soft feel as the hand-made version. 

I love hand-crafted products, which is why I'm pleased with how these pieces came out in the end. Looking at them now I can feel every edge, see every slight misalignment, and remember the focus required of the process. As a creative person, this is like a drug to me and I would eagerly take on another round of the same. Next time I'll even know a little about how to do it better.

While the misalignments were not a deal breaker, they're the one part of the process that I would want to improve on in the future. It's simply a matter of developing a better way to retain the lens alignment while exposing the glue for fastening. I've pondered a simple clamp system to hold the lens and the print steady at one end, allowing for half to stick in place before continuing with the rest. It's just an idea, but I think it would solve the problem of each lens shifting when it's moved to peel back its protective film.

Then I wonder if that would ruin the outcome as it might make each piece too homogenised by precision. There's an elegance to the subtle differences between each piece that speaks to its handmade construction. There's a beauty in the slight differences between each lenticular print that I would probably miss if they were all as machine-perfect as each other.

To round out this rather lengthy post-mortem; I have to say that I'm pleased with the outcome of the entire project. Speaking on a personal level, it's always satisfying to learn new things and I was reminded at how much I enjoy crafting pieces with my hands. There were times where I'd look out the window of my office to re-focus my eyes, and steal a small moment of gratitude for being able to work at something fulfilling.

I hope there are many more moments like that in the future, as we should all be so lucky to love what we do, and have the opportunity to do what we love.