Understand, no one makes the epoxy, they only package it. That likely includes even Devon. They buy it in 55 gal (45 imperial) drums from the manufacturer.
You can pick which formulation you want, pot life, mix ratio, strength. You can then add stuff, like Carb-o-sil , a thickener and firmer, mini fibers, another thickener and strenghtener, or fiberglass, another thickener and a even greater strengthener.
I use earth pigments to get the brown. Burnt Umber. The local plastic dealer has a rack of dyes for fiberglass, I imagine they would work for epoxy.
