Hi there. I am having an issue with Castin Crafts black pigment separating in my resin. I’ve tried a few different resins and with each, the black pigment separates from the resin within an hour of pouring in to a bezel. The pigment “pools” in the bezel and then the rest of the resin looks clear. I only have the issue with black pigment. All other colors mix well. I’ve tried a new bottle of pigment, but that didn’t make a difference. Has anyone had this issue before?