Can You Use Crayola Markers on Shrinky Dinks? A Quality Manager’s Honest Test

Last Tuesday, I opened an email with a subject line that looked like someone had spilled a search bar onto a form. Under “urgent,” the teacher had written: “Can you use Crayola markers on shrinky dinks? Also, is the Crayola Body Wash Pen the same as a marker? Do you have a height percentile calculator or aft calculator? And how does a 3d printer work?” I laughed. Then I did my job, because at least one of those questions was actually about markers.

I’m a quality and compliance manager at Crayola. I review every label proof, classroom guide, and sample before it reaches customers—roughly 200 unique items a year. Maybe 180, I’d have to check the system. In 2025 I’ve already rejected 12% of first submissions, usually for instructions that don’t match the product’s tested behavior. If you ask me, that’s what quality control is really about.

I made the rookie mistake once in my first year. I told a teacher “yes, our markers work on shrink plastic” without testing the actual batch. It cost us a classroom’s worth of trust and a lesson plan. I’m not going to repeat that here.

Testing markers on shrink plastic

The short answer: it depends which marker. Standard Crayola washable markers are water-based and designed for paper. On smooth plastic they bead up, and in the oven they don’t get better. What I mean is: they’re not the tool for this job. Our Crayola Permanent Markers, however, are made for non-porous surfaces, and they held up well in our bake test.

To make the test fair, I asked our model shop to cut a stencil. That’s where the 3d printer part comes in. If you’re wondering how a 3d printer works, the simple version is: a printer melts plastic filament and lays it down one thin layer at a time, like a hot-glue gun with a path plan. It’s not magic; it’s just tedious geometry. We printed a dog-bone shape, traced six identical pieces of shrink plastic, and colored three with permanent markers and three with washable markers. Don’t hold me to the exact shrink ratio—I’d have to pull the report—but it was significant. Around 45%, give or take.

Here’s the twist. I almost approved a classroom guide that said “Crayola markers work on shrinky dinks.” The upside was a simple answer for teachers. The risk was that they’d use the washable markers that are in every school supply list and end up with smeared, uneven plastic. The downside felt catastrophic. So we ran the test instead of guessing. The permanent markers darkened slightly and kept their shape. The washable pieces looked like something from a bad science experiment.

I’m not saying washable markers are bad. They’re excellent for the classroom precisely because they wash out of skin and fabric. What I mean is they aren’t designed to survive an oven. At least, that’s been my experience with our 2024 reformulation. But shrink plastic is not paper.

The body wash pen question

Now, the Crayola Body Wash Pen. It is not a marker for shrinky dinks. It’s a bath-time product shaped like a pen, designed to wash off skin. Put another way: if you draw on your child’s arm with it, it rinses off in the tub. But it is not an art material. I’d no sooner recommend baking it than I would recommend turning a bar of soap into a crayon. Different product, different test file, different purpose.

The teacher’s email also included height percentile calculator and aft calculator. I genuinely don’t know what “aft calculator” means in her context. I could invent something, but that would be the same mistake I made years ago with the shrinky-dinks answer: guessing from a place of authority. A height percentile calculator is a pediatric growth tool; it is not something we keep in the art supply compliance office. If you need a growth chart, please ask a pediatrician or a reliable public health source. If you need an aft calculator—whatever that stands for in your field—find someone who owns that topic and ask them.

What I actually did with the test results

Once the bake test was done, I rewrote the classroom guide. It now says: yes for Crayola Permanent Markers, not for standard washable markers, and always follow the shrink plastic manufacturer’s directions.

I also checked the words we use on the packaging. When we call something recyclable, we have to be careful about it. Per FTC Green Guides, a “recyclable” claim should not be on a package if most people can’t actually recycle it. That’s why you’ll sometimes see “check local recycling” instead of a blanket statement. It feels less tidy than a single word, but it’s honest.

And a practical shipping note: I mailed a test sample and a copy of the guide to that teacher in a large envelope. According to USPS pricing effective January 2025, a First-Class Mail large envelope (1 oz) costs $1.50, and each additional ounce is $0.28. That’s not a Crayola fact, but it was part of the project, and I don’t want to send teachers out with budget surprises.

The lesson I keep learning

If you ask me, the most credible thing a company can say is “this is in our lane, and this isn’t.” We know washable markers, permanent markers, and how they behave on different surfaces. We do not know medical calculators, unexplained acronyms, or every possible use someone invents for our products. The moment we pretend otherwise, we stop being useful.

So here is my official answer, tested this time: Can you use Crayola markers on shrinky dinks? Use Crayola Permanent Markers. Don’t bake washable markers. And if you came here looking for a height percentile calculator, an aft calculator, or instructions for a 3d printer, that’s okay. But this article is about markers—and it’s all the more reliable for not pretending to be about everything.