How much Cactus Juice does each blank take?

It is really not possible to estimate how much resin each blank will take since that completely depends on the blank itself. A general avergae is somewhere around .2 to .3 ounces per cubic inch.  In other words, a blank that measures 1" x 1" x 5" averages somewhere around 1-1.5 ounces of Juice per blank.