So I have been working with resins and silicones for a long time now and over the past year or two I have been working with expanding foams. Flex Foam IT is an expanding foam series from Smooth on and is an excellent way to build castable fursuit head bases, noses, fursuit toes, and so much more. There are many different expansion and density rates in this line, the one I am using here is "X". While I do very much like the X in the series it is not recommended for something like fursuit toes (In my opinion, other people may disagree, but this is from my experience). The density of the foam is just a bit too heavy and causes the toes to fall forward, which could knock your shoe off or cause you to trip... NOT fun in a fursuit, right? Instead I would recommend something with a slightly lower density and bigger expansion rate for toes, such as the Flex foam IT 6 which will expand 10x its volume.

However this does not mean that the flex foam it X is unusable in fursuit construction, it actually would make for a very durable fursuit head base or used on casting noses as well.


Also one quick tip for when casting expanding foam! Be sure to cast all at once, do not let it expand in half of your mold, cure, and then pour more. This could result in improper curing or you could be left with parts of your mold being quite hard.