How do I measure this product by weight or volume?

Deep Pour Epoxy Resin is measured by volume and mixed in a 2:1 ratio. For instance, four ounces of epoxy would require two ounces of hardener for a proper solution. Mix the two parts into a small container mixing only what you need as your project progresses. Casting resins have a lower viscosity and may be poured several inches in thickness at a time. Plus, their slower curing rate provides for a longer working time.