When you’re making costumes out of foam, you might have noticed that when making a pattern that wraps around, like bracers, the thicker the foam, the more length you have to add to compensate for the thickness.  You could always guess how much, but that can be risky if you under measure, and more work if you over measure.

Here is a tip and an easy tool that you can make and use for making all your foam fabrication patterns!  To put it simply, it’s just a ruler made out of the same foam as the floor mats that you’re making your armor out of!  Here’s a list of what you’ll need to make one!


24″ metal ruler– This will be a straight edge for cutting and to mark your measurements with, longer than 24″ is fine, but no shorter.  You can get these at any art supply, office supply, or hardware store.
Black pen– for marking your cut lines and inch increments on the foam ruler.
Markers–  You’ll need at least 2 different colors!  Try and get fine tip markers.
Cutting tool–  You’ll need a cutting tool, and make sure it’s sharp!

Once you’ve gotten all of your materials,  mark two straight parallel lines on one edge of your foam about 1.25 -2″ wide and all the way across.

You’ll have the puzzle piece nubs on the ends, you’ll want to get rid of those.  You can get 22″ out of your standard floor mat, longer if you go diagonal but that’s a waste of foam.  Mark out 22″ and cut the nubs off.

Using your black pen, make a mark every inch. Draw a line straight across, and be sure to get the sides as well.

Now grab your color markers!  Pick a color, any color, doesn’t matter.  Just make sure that the 2 colors that you choose are different enough from each other.  For this I used green and red.  Every five inches, mark the line with the red color marker. Do this the whole way down and be sure to get the sides.  Now go back with your green  marker and make a dot every 2 inches, and same on the sides.  The reason for these color lines and dots is so that it’s easily recognizable when you’re using it, and you don’t have to count out every single inch or take the time to mark every singe inch.

To show you how to use it, and just how much of a difference there is, here’s what my forearm is with measuring tape, and then what my forearm is with the foam ruler!  Now when you’re making your foam armor patterns that wrap around like bracers, shins,etc, you won’t have to second guess your measurements.

If you like this tip and want to learn more about foam fabricating, check out my e-book or my older weekly fabrication tips!