Yesterday, I spent 5 hours at the torch experimenting with some new frit (for those of you learning about glass, frit is ground glass that gets applied to a base bead). I learned alot about the frits I was using, but very few of the beads are presentable! One of my favorite frit colors, copper blue, turned to black on most of the beads I made. So I learned that copper blue reacts with the chemicals in most of the plain colors, ivory, white and silver leaf - so much so that it turns black. There needs to be caution on the copper blue frit that says not to overwork (heating the bead to orange glow over and over) the color. I was using the Italian glass, I'm thinking that I've used the copper blue on the American made glass and it didn't turn to black. I'll have to do some more testing with it to see.
I've mentioned this before, but this is what I mean about being a "hands on" learner - I have to make all of these mistakes and make all of these rotten beads to learn the properties of the glass and how color works in glass. Color in glass isn't the same as mixing paints or pastels or even colored pencils. The compounds that create the color will interact with certain other compounds and you may get a great color or you may not. This weekend I didn't get much of anything. I hate when that happens!