: I'm not sure for sure, but I think Shawn Baker has used toner for coloring.

I used it to darken the epoxy for my hatch lips.

I found I had to add a little glass microballoon filler to make it more opaque. While the toner makes the epoxy jet black, it's sort of a translucent jet black. Just a few teaspoonsful of the microballoons made the blackened epoxy very opaque and still jet black. (The micro.. are white) No evident problems with wax, "stickumtivity", etc.

Shawn