If you need to cut foam for your latest project, you've got several easy options. To make just a few, simple cuts, you can cut the foam manually. Take scissors, a simple blade, cookie cutters, or even dental floss and cut through your foam. To make larger cuts, use electric tools. Secure the foam and use an electric knife, hot wire cutter, or foam saw to cut through thick or firm foam.

Method 1
Method 1 of 2:

Cutting Foam Manually

  1. 1
    Use scissors to cut through soft foam. To cut thin or flexible foam, get out a pair of heavy-duty scissors. You can cut curves or straight lines, but you may want to lightly draw your design on the foam with a permanent marker before you begin cutting. Make long smooth cuts so you don't get choppy edges in the foam.[1]
  2. 2
    Wax a blade to cut the foam. For basic straight cuts, choose a blade with a handle that's comfortable to hold. You could use a utility knife, old kitchen knife, bread knife, or box cutter. Take a white candle and rub it against the blade before you slice through the foam. The wax will make the blade slide smoothly in the foam.
    • It's best to use these simple blades with soft or thin foam.
    • If the blade begins to catch on the foam, just rub the candle on the blade again.
    Advertisement
  3. 3
    Cut the foam with cookie cutters. To cut soft or rigid foam that's 1/2-inch (12 mm) thick or less, lay the foam flat on your work surface. Select a metal cookie cutter in the shape you want to cut and press it down evenly through the foam. The cutter should cut completely through the thin foam.
    • You may need to press against the foam to pop the cut piece out.
  4. 4
    Slice through foam using dental floss. If you're trying to cut through sheets of thin foam, pull out a long strand of dental floss. Place the dental floss on your work surface and lay a sheet of foam down on the floss. Position the sheet so the floss lines up to where you want to make the cut. Hold the foam with one hand and use your other hand to pull the end of the floss towards you.
    • Dental floss works best for straight cuts. If you want to cut through multiple sheets of foam, slice them separately to get clean cuts.
  5. Advertisement
Method 2
Method 2 of 2:

Using Electric Tools

  1. 1
    Secure the foam to your work surface, if necessary. If you're using a foam saw that's attached to your work surface, you'll be able to move the foam as it's cutting. However, if you're using an electric knife or wire cutter, you should keep the foam from moving while you're cutting it. You can hold the foam with one hand, secure it to the table with clamps, or set the foam in a vise.[2]
    • Ensure that the part of foam you'll be cutting extends away from the clamps or vise so you have room to cut it.
  2. 2
    Wear protection. Always use caution and wear eye protection when you're using electric cutting tools. If the cutting will make fine foam dust, you should also wear a face mask to avoid breathing it in.[3]
  3. 3
    Use an electric knife. To cut through thick or stiff foam (up to 4 or 10 cm thick), stack the foam together. Plug in an electric knife and turn it on before you touch it to the foam. Use the thinnest blade on the knife to make straight or curved cuts. Go slowly through the foam as the electric knife cuts so you get a clean cut.[4]
    • If you're cutting a very soft foam, avoid pushing down while you cut with the electric knife. This can make it difficult to cut or can move the blade away from where you want to cut.
  4. 4
    Cut foam with a saw. If you cut a lot of foam on a regular basis, consider buying a foam cutting saw. The saw is supported by a base that you set on your work surface. The blade runs vertically, so you'll hold and move the piece of foam against the blade to make your desired cut. If you'd rather hold the foam and move the saw, you can remove the base on most foam saws, or use a common jigsaw for thinner foam boards.[5]
  5. 5
    Heat a wire cutter to cut through the foam. Plug in a small wire cutter until the wire is hot. Avoid touching the wire. Push the foam through the blade to make straight, smooth cuts. If you'd like to cut more details (such as waves, curvy lines, or circles), consider using a hot wire foam cutting table.
    • You'll be able to select the thickness of the blade when you buy a hot wire cutter. This will determine the size of foam that you're able to cut through.
  6. Advertisement

Things You'll Need

Cutting Foam Manually

  • Foam
  • Heavy-duty scissors
  • Blade (such as a utility knife, old kitchen knife, bread knife, or box cutter)
  • White candle
  • Metal cookie cutters
  • Dental floss

Using Electric Tools

  • Foam
  • Electric knife
  • Foam saw
  • Hot wire cutter
  • Hot wire foam cutting table (optional)
  • Eye and face protection
  • Vise or clamps

About This Article

Jessica Gibson
Co-authored by:
wikiHow Staff Writer
This article was co-authored by wikiHow staff writer, Jessica Gibson. Jessica Gibson is a Writer and Editor who's been with wikiHow since 2014. After completing a year of art studies at the Emily Carr University in Vancouver, she graduated from Columbia College with a BA in History. Jessica also completed an MA in History from The University of Oregon in 2013. This article has been viewed 109,750 times.
70 votes - 81%
Co-authors: 5
Updated: May 6, 2022
Views: 109,750
Article SummaryX

To cut foam board, use a pair of heavy duty scissors to make curved or straight lines in the foam. Alternatively, use a utility knife or a bread knife to make the cut. You can make the blade cut through the foam more easily by rubbing candle wax onto the knife. If you want to cut foam that's 1/2 inch thick or less into a specific shape, try using a cookie cutter. For thicker foam, clamp it to your work surface and cut through it with an electric knife. To learn how to cut foam using dental floss or a saw, keep reading!

Did this summary help you?
Advertisement