Mirkaba: I am a believer in using basanite and other colored stones for backing. If you are selling them I hope you tell your customers. One thing I will caution about using electrical tape. IT gets bad with age. It can get gummy from heat and dries out when it gets really old. My feelings are sticking with natural backings that will last a life time.
I am not making a doublet or triplet. I use Basanite all the time for that purpose. I cut a piece sometimes 2 and use it in place of leather,sawdust, plastic etc. like a cushion. I met a fellow from Lightning Ridge that used black marker on crystal Opal. I couldn,t do that.
Basanite is a very dense black Basalt usually used for backing on thin sliced opal when making doublets and triplets.
