What's in Dry-Erase Markers? | Ingredients With George Zaidan (Episode 10)

What's in here? What does it do? And can I make it from scratch? Pick the stuff, it's on your stuff.

Ingredients: Dry erase markers are magical. I mean, you write on a smooth, hard surface like this dry erase board or a mirror, and then whatever you write is almost 100% erasable without using any liquids. This is insane!

Now, normally this is the part of the show where I take the product package, turn it around, and show you the ingredients list, and as you can see, no ingredients list. This is not just for dry erase markers; office products in general don't usually have ingredients on the back. So figuring out how this stuff works is gonna be a job for Curious Chloride, Chemical Detective at Lourdes.

That makes no sense. Well, there are no chemical names that rhyme with detective. Change back! Luckily we have these: these are MSDS, or Material Safety Data Sheets. Now companies are required to keep these on hand for any product or substance that an employee might have some sort of safety concern about.

Now, if you have no life, like I do, and wade through all 40-plus MSDSs of all the dry-erase brands, not just this one, you will find one that is helpful. So let's take a look at this more detailed ingredients list.

Okay, I don't really care so much about the pigments. What I want to know is, how does the mixture of alcohols, octadecanoic acid, tri-ester, chemically modified polyvinyl alcohol, and hexanoic acid blah blah ester come together to make a dry erasable ink?

Except the thing is, if you look these ingredients up online, you will either find that they have a bajillion listed uses or none. Now normally, this is where I would turn to the scientific community for help, but no one seems to be doing a ton of research on how dry erase markers work. I guess they have better things to do. The dry erase marker companies have probably done all this work, but all that information is proprietary.

So what do we do? Patents! Yep! Turns out there is one key patent that explains the whole thing. Basically, dry erase ink is a mixture of five different things: solvent, resin, pigment, release agent, and wax. And the wax we can ignore for now because it's kind of a wild card. The resin and the pigment, you can think of as one thing. The point of the resin is to help the pigment evenly spread across the surface.

So our simplified system is actually three things: solvent, resin, pigment, and release agent. And the magic is something that you probably slept right through in high school: solubility. You choose the ingredients based on whether they do or don't dissolve in each other.

So when the dry erase marker is just sitting there on the table, the solvent has to fully dissolve both the resin, pigments, and the release agent. But when you write on a whiteboard, that solvent is going to evaporate, leaving only the resin, pigment, and the release agent. And this is the key part—the resin pigment has to not dissolve in the release agent.

So on the whiteboard, they separate out into two layers, just like oil and water. The release agent is the layer closest to the board, and the resin pigment is on top of that, but it does not stick to the board. So when you wipe, the resin pigment comes right off, and the release agent can come off too, or it can stay on the board as long as it's colorless.

Good God, man! That's brilliant! And from what I can tell, the biggest difference between a dry erase marker and a permanent marker is that the permanent marker does not have a release agent. So here, the resin pigment just sticks to whatever you're writing on, and you cannot get it off without some sort of solvent.

Now, what about that wax? Well, it turns out that's another bit of genius. If you leave the marker sitting out like this for a long period of time, the wax is supposed to form a thin film on the outer surface of the tip that prevents solvent from evaporating. Then when you go to write on the board again, friction between the tip and the board breaks up the wax and lets the ink flow.

Okay, so that's it! We're done. Nope! Because even though we have a general idea of how dry erase inks work, we don't know if it makes sense given the exact chemicals in our MSDS. But as Curious Chloride would say, let's find out!

So first up are the alcohols, ethyl alcohol and isopropyl alcohol. Now if you've guessed that these are the solvents, you are 100% right! Because they're used in other products as solvents and they're actually also listed in the patent as potential solvents. So, well-done!

Next up: chemically modified polyvinyl alcohol. Now that's a bit of a mystery, but if you look it up by ID number online, you will find that it's also called polyvinyl butyryl, and that is listed in the patent as a resin. So we're good on solvents and resin.

Next up: hexanoic acid to ethyl hexadecanoate ester. Now this is where things get complicated because the patent says you can use an ester made from an acid with 12 to 22 carbons and an alcohol with 1 to 5 carbons. Do not worry about that at all; it's not important. The point is, hexadecanoic acid blah blah ester almost fulfills that, almost, but it's close enough, so I'm going to say that is our release agent.

Which might leave you thinking that octadecanoic acid tri-ester is our wax. Except it's not a wax! It's not even remotely similar to wax. It's much more similar to an emulsifier found in peanut butter than a wax. So we found our solvent, our resin, and our release agent, but instead of a wax, we found what I think is an emulsifier.

So a couple things could be happening here: either they just say to hell with the wax, we're not going to use it, or maybe the release agent also acts as a wax but needs an emulsifier to stay in solution. I'm afraid we will never know unless one of you cares to enlighten us in the comments.

Now that we have a decent idea of what's in dry erase markers and how they work, I'm gonna try and make my own from scratch using only natural ingredients. So I've got ethanol, acetone, and cetyl alcohol, all three of which you can get from nature. I also have this blue ink, which honestly I have no idea if it's natural or not; I just had it lying around the house, so I'm going to use it.

Now, given the detective work we had to do to figure out what's in dry erase ink, I'm reasonably sure this recipe is going to fail completely. But you know what? That's the way science works sometimes. So let's just roll with it!

Here we go! I'm going to stir this, and we didn't actually heat it that much, so I think, I think we can go ahead and test this right now. Now I'm going to use some paper towel as a makeshift felt tip marker here, and I'm going to write on the board. Here we go!

Okay, now moment of truth. There we go! Ah, no! Actually, hey, wait a second! Guys, that's not bad! I mean, I definitely left some smudgy smudge on the dry erase board, but a lot of this ink came off on my petal! I am NOT disappointed with this! This is a six out of ten; this is solid work, especially for a first attempt!

I bet if I added a little bit more cetyl alcohol, I'd leave even less of a smudge! So overall, I'm happy with that! I really am! If you guys have ideas on how to improve the recipe, let me know in the comments or hit me up on Twitter. And if you have an idea for another episode, definitely let me know.

Okay, good job detectives, well done! Yes! Okay, good! Yeah! Haha! Why? Where? What have I done?