Things You'll Need:
- Foam Board
- Utility Knife
- Spare Utility Knife Blades
- Pencil
- Metal Ruler / Straight Edge
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Step 1
You Will Need A Few Supplies Before You Get StartedTo prepare for cutting foam board, you will need to get a few basic supplies.
You will need:
Metal Ruler / Straight-Edge
Utility Knife
Extra Utility Knife Blades
Lead Pencil
Eraser -
Step 2
Use A Mechanical Pencil To Draw Your Pattern On The Foam BoardDraw your pattern on the foam board with the lead pencil. I use the mechanical pencil type so I don't have to keep sharpening the pencil. In the project pictured, I was making a large number "4" out of a single piece of foam board. This is a standard piece of foam board measuring 20" x 30" x 3/16".
Using your metal ruler, measure the dimensions of your design and draw it on the board very lightly with the pencil. Don't press hard and make a dark line, as this is not necessary and will just make it harder to erase the line later. -
Step 3
Cut The Foam Board At A 45 Degree Angle With The Utility KnifeAfter you have drawn your design, get your utility knife and the metal straight edge. It is important that the blade in your utility knife is very sharp so that it makes as clean a cut as possible. If your blade seems to be getting dull after several cuts, change to a new blade to avoid tearing the foam or getting uneven cuts.
Before you cut, lay your foam board on top of a thick piece of cardboard. This will allow the blade to cut through the bottom of the foam board without harming anything underneath it.
Place the metal ruler along the pencil line you want to cut. Hold the ruler down firmly with one hand so it will not move. With the utility knife in your other hand, place it's blade up against the metal straight-edge. Hold the knife so it's blade is at a roughly 45 degree angle to the board. Press the tip of the blade down into the foam board so that it goes through the top layer of poster board and part way into the foam layer. Keep the blade pressed against the metal ruler as you go to keep your cut straight. Cut the board through these two layers to score the board, and then go back over the cut a second time to finish cutting through the foam layer and the bottom poster board layer. The foam board will usually cut cleaner this way if you score it first instead of trying to cut through all three layers at once. -
Step 4
Erase Pencil LinesAfter you have made your cuts, you can trim away any rough edges that might be left. Erase any pencil lines that are still showing on the board's surface. This is when you will be glad that you drew your lines lightly, as too much rubbing with an eraser can mar the surface and take the color off the foam board!
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Step 5
Follow These Steps And The Foam Board Should Have A Clean Straight EdgeYour finished foam board should end up with a clean, straight edge!















