Working with foam board for art projects; cutting, painting, etc
Published September 7th, 2015. Updated August 12th, 2026.
I use cheap foam board (aka foam core) from the dollar store as the base of most of my sculptures and masks. I like using foam board because it can be cut/glued/etc with lots of precision. You can make things nice and symmetric, or a very specific size, etc.
Buying foam board
I buy all of my foam board at Dollar Tree. It used to be a dollar for a 30"x20" sheet; in recent years it's gone up to $1.25 per sheet. Sometimes they're out of stock at the store, and in that case I order it in bulk from their website; they sell it in boxs of 25 sheets. I go through usually two or three boxes a year.
Beware: the nice foam board they sell at art stores is much more expensive, and I find it harder to work with. It's denser so it's harder to cut, and it can't easily be be curved or bent or rolled up; more on that below.
Cutting foam board
I use an X-acto knife for cutting foam board. It's important to use a new, very sharp blade. Be very careful! Never cut toward yourself. (Always cut toward someone else.) This may sound weird, but a newer/sharper blade is safer to use than an older/duller one. Why? With a dull blade, you have to apply more pressure, push harder on it, etc, and that makes it more likely to jump out of what you're cutting. "That's ridiculous, that would never happen to me." I'm here to tell you it's happened to me many times.
When cutting foam board, try to keep the blade very perpendicular to the surface, straight up and down, not leaning to the side. For a lot of projects, it helps to have the edges of your foam board pieces nice and square, rather than diagonal.
Before cutting, protect your work area with something thick, like cardboard (I recommend two layers!), or coroplast — I like stealing advertising illegal signs for this — or even another sheet of foam board, but that's a bit wasteful.
Curving/bending foam board
One great thing about cheap foam board from Dollar Tree is that you can bend it, curve it, roll it up, etc! For small pieces this is really easy to do, although there's always a risk it could crack or break. Masking tape can help protect the foam board from cracking, either before you mess it up or afterward. Masking tape is fairly stretchable so it works well for this.
For larger pieces of foam board, it can physically difficult to curl or roll it up, but it's doable. Let's say I want to make a large tube. I lay the sheet flat on my table, and starting at one edge, I press my fingers into the sheet and curl the edge upward with my thumbs. You want to crush the foam with your fingers as much as possible, and as you lift with your thumbs you can begin to roll the sheet upward, curl it in on itself and continue from there. The more you crush up the entire surface of the foam, the easier it will be to curl, and then smoother the outer shape will be. If you don't take the time to really crush up the foam inside, you'll get visible ridges in the outer surface of the tube. You can also re-do the curling/crushing step multiple times to really soften up the foam.
Connecting pieces of foam board
Hot glue, masking tape, and shipping tape are all good for connecting foam board pieces, or connecting other materials to foam board. (Elmer's glue and wood glue are fine, too, but they take a long time to dry.)
Here's a trick: Imagine you take a small rectangle of foam board and curve it. It'll hold the curve, but it won't be sturdy; you could easily bend it back in the other direction. Now, imagine taking a second identical shape, then put the same curve in that, and now glue or tape the two curved shape together. Now they'll hold the curve perfectly and be very sturdy.
Here's an old pic that sort of illustrates this. For this antler, I cut out two copies of the same shape, taped them together at the base, and then curved them together and taped them a few times along the length. If you do this with just one copy, it won't hold the curves, but with two copies together it's very sturdy. It's like each shape is preventing the other from going back into its original position.
Painting foam board
There are a few important caveats for painting directly on foam board. The main thing to be aware of is that foam board is actually a sheet of foam with a layer of thin paper on each side. This paper is porous, and when you apply paint to it directly, the paper can warp, it can wrinkle, it can get become soggy and tear, and it can separate from the foam entirely. Personally I try to avoid painting directly onto foam board for these reasons. All of my masks and sculptures end up covered with paper maché, and it's safer to paint on that.
One option for certain projects is to remove the paper entirely. To do this, all you have to do is soak it in water for a little while and then peel the paper away. You can then paint directly on the remaining foam surface, and you won't have any of the problems I listed above. However, without the paper coating, the foam is much more brittle and can break easily.
Making foam board stronger
For certain projects I may need a flat surface that's stronger than just a sheet of foam board. My solution for that is: two sheets of foam board, glued together, and covered in paper maché. With six or more layers of paper maché on two layers of foam board, you end up with an object that almost feels like lightweight wood. You can also make this kind of thing stronger by putting popsicle sticks or wooden coffee stirrers between the layers. I've totally made shelves this way; it works!
Paper maché on foam board
Here's something to watch out for! Let's say you make a foam board shape, and you apply paper maché to one side of it. As it dries, the paper surface of the foam board can shrink and cause the foam sheet to warp, sometimes severely. Sometimes you can correct this by putting heavy books on the piece for a couple days to flatten it out, but sometimes it's just not possible.
One thing that will prevent foam board from warping is to cover it in tape first. You can then cover the thing with paper maché, and the tape won't warp and shrink the same way the paper surface of the foam board does. The piece might warp a tiny bit, but nowhere near as bad as it would without the tape. I use this trick all the time whenever I'm making something with flat surfaces, like a box.
What about cardboard?
What about it?
Couldn't you use cardboard for all of this?
Ah! Sort of. Cardboard is great because it's free. For me and the types of projects I do, there are a few downsides to cardboard: I find cardboard harder to cut cleanly. Different pieces of cardboard often have different properties; different thickness, different stiffness, etc. So it's less consistent and reliable. Also, cut pieces of cardboard usually don't have a nice flat edge like cleanly-cut foam board does.
Have fun!