Whether you’re using foam board as insulation, for building material, photography mounting, or crafting, you probably want to know how to cut it cleanly and quickly. You want to get through the foam with ease, but you also don’t want to leave a ragged edge, and you definitely don’t want to create toxic fumes in the process. But there are just as many ways to cut foam as there are types of foam, so we’ve created this review-packed guide to help you sort out the various methods and tools that will get the job done. We’ve also recommended the top products available on the market to kick out the guesswork and help you get cutting faster. Read on to learn about our top 5 picks that will help you decide where to start.
|Rank||Model||Our Favorite Product|
|#1||A Long Bladed Utility Knife|
(Our Preferred Way)
|Slice 10559 3″ Extra Long Industrial Knife
|#2||A Hot Knife||RoMech Foam Cutter – Pro Electric Hot Knife (200W)
|#3||An X-Acto Knife||Xacto X5282 Basic Knife Set
|#4||A Hot Wire Cutter||Hercules Tabletop Styrofoam Hot Wire Cutter (CT-115)
|#5||A Foam Cutting Saw||Acu-Cutter 350 Foam Saw w/ 8″ Blade
The versatility of a utility knife with a long blade makes this our top pick. You can use it for most thicknesses of foam, including for crafting or foam board insulation. Make sure you choose a smooth blade, though (not serrated), to avoid those ragged edges. You’ll want to apply some weight to the foam board to keep it from sliding (turn foam board insulation flat side up) and cut in one smooth motion at about a 45-degree angle. If you start sawing at the board, you’ll end up with ugly edges and little foam shreds flying everywhere. Check out our pick below for a good-quality utility knife that will get your job done quickly.
We recommend the Slice 10559 3″ Extra Long Industrial Knife:
When a standard knife won’t cut it, you might need some power. A hot knife can give you power along with freedom of movement, which makes it our second pick. Like the long-blade utility knife, it’s also great for varying thicknesses of foam. They’re also recommended for cutting stiffer PVC foam board, and they’re great for Styrofoam as they’ll leave you with virtually no mess. As with any heating element against foam, check the manufacturer recommendations, as some foam types can off-gas toxic chemicals. If this is the case, you can always wear a mask and goggles before cutting. Check out our top pick from the hot knife market below. It will get you cutting through foam with ease.
We recommend the RoMech Foam Cutter – Pro Electric Hot Knife (200W):
While this method is going to serve you best for thinner foam boards, such as those used for crafts or photo-backing, the dexterity and control you’ll get from an X-Acto knife makes it one of our top picks. Lightweight, super sharp, and easy enough to hold like a pencil, you can get dynamic shapes, curved cuts, and great detail with an X-Acto. On the downside, you won’t want to rely on one of these for thicker foam, especially the type of foam board used in construction. The amount of effort and pressure you’ll need will give you nothing but a headache. Stick with an X-Acto for foam thicknesses less than 1 inch. As with the long blade utility knife, you’ll want to cut in a smooth motion without sawing to keep your edges clean. Check out the set below, which includes multiple interchangeable blades to give you versatility in your projects.
We recommend the Xacto X5282 Basic Knife Set:
Cutting thick foam can be a big job, but it’s nothing a hot wire cutter can’t handle. Designed to slide effortlessly through foam and leave perfect edges, these cutters can provide diversity in the way you cut. They’re great for crafts and intricate cutting, as well. While you’ll need to use extra caution with fumes (check the foam manufacturer for recommendations on heating it) and be careful with the heat, you can save yourself a lot of effort by using this method. They come in different styles, too. The first is a tabletop model with a square and measuring ticks (which we recommend), and the second is a handheld device that comes in either a wand style or an arc. For ease of use, a tabletop device is perfect. Check out our top pick below.
We recommend the Hercules Tabletop Styrofoam Hot Wire Cutter (CT-115):
On the opposite side of the spectrum from the X-Acto knife is a foam cutting saw. If you need to cut large amounts of thick foam, an electric foam saw will spare you countless hours of manual labor and grip fatigue. Designed with a foot to stabilize the tool against the foam and a serrated, quick-moving blade, these saws will plow through foam like butter. Because of the quick, powered blade movement, you’ll also end up with smooth edges. On the downside, it could leave a mess of foam particles in your work area. They’re also on the higher end of the price spectrum. Check out our top pick below for the best electric foam saw of 2020.
We recommend the Acu-Cutter 350 Foam Saw w/ 8″ Blade:
While you have many options for cutting foam, the best option is almost always the simplest. A long-bladed utility knife will perform perfectly under most conditions, and they’re versatile enough that you can use them for other materials, as well. If you have a big project, consider a power tool such as the hot knife to give your hands a break. You’ll still get beautifully clean edges efficiently and quickly. No matter what you choose, be sure to steer away from anything with teeth or that requires a sawing motion, as you’ll ruin your edges and leave a mess of foam shreds in your workspace. But the great thing about foam is its softness and pliability, making it easy to work with. You can purchase an inexpensive tool and still have great success.
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We hope these product reviews have helped you decide on the best tool and method for your needs. Remember to keep it simple for the best results. If your job is a big one, go for some heat. If you’re crafting or using thin sheets, go for small and sharp. Smooth strokes will get you clean cuts, and you’ll want to avoid serration unless you want to clean up the mess afterward. Good luck finding the perfect product. Now go tackle that foam!
Ryan is a freelance writer from Arizona. When he's not blogging about his favorite hobbies, he's writing fiction, hiking or running in the great outdoors, and spending time with family.