Aquarius

Aquarius – A powder blend that conjures a fine bluetone onto your bead .

Powder blend made of reactive glass powder/frit.

Simply roll your bead in the powder blend and let the powder melt in, then use glass as wanted (finish your bead or pull stringers for scrollwork). 
If you paint with e.g. turquoise, light blue, ivory (“weak” colors) stinger onto a base of Aquarius, the powder blend reacts with the glass: the effect is a dark line in the middle.