I like using plexi-glass for mold walls so that you can see that whatever material you are pouring is getting even distribution (but really it just looks cool).
I decided to pour a block of rigid polyurethane foam so that I could carve it into positives for other sculptures, specifically for my line of wearable arduino enabled reactive sculptures which I will show you some progress on in tomorrows post!
I really like to carve in foam because you can use all of the wood carving tools like gouges and never have to worry about the grain. Foam carving is easy breezy baby.
