1 - Plain (reduced), 2 - Plain, 3 - w/ Silver Leaf, 4 - w/ Silver Leaf (reduced & encased), 5 - w/ Silver Glass Frit (reduced), 6 - w/ TerraNova2 Frit, 7 - Silver Glass Frit Stringer (encased), 8 & 9 - w/ Tuxedo, Copper Green, Opal Yellow, Ivory, Peace
Effetre Cobalt Transparent is a deep, rich cobalt blue transparent. It is moderately saturated, meaning that while it is a nice, dark colour, it still looks blue rather than black when used to make spacer beads. It is moderately reactive with silver and other glass colours, making it an interesting addition to my palette.
It's sort of funny to me now that I've been avoiding this colour for the last six years or so. I always regarded it as too bright or something, and never wanted to use it. I had no idea how much I was going to like it once I tried it. I guess I'm getting over my fear of bright colours or something.
On top of Cobalt, silver more or less stays put and forms a fine, webby network. When it is reduced and encased, it takes on a blue/green appearance under the clear.
I read a post on Lampwork Etc. by Sarah Kay about her Blue Bead using this colour and silver, which you should also read if you are interested in how to really exploit the effects you can get by reducing and encasing this colour.
The results I got from putting silver glass on top of Cobalt, for lack of a more descriptive set of terms, is just sort of odd. More experimentation is going to be required to figure out whether it is good-odd or bad-odd. The reducing silver glass frit got beautiful colour and some interesting curdling and outlining effects on top of Cobalt, and my TerraNova2 frit developed colour well, but in a murky purple way that I'm not sure I'm a fan of.
Using Cobalt in my silver glass frit stringer test yielded a partial success. It is interesting that it did something, even if that something isn't what I am usually hoping for in this test's results. It's wispy, and not solidly streaky like I have experienced with other reactive transparents like Yellow, Straw Yellow, Light Brown, etc.
Unfortunately, in the right-most bead, I seem to have done two stringers of Opal Yellow instead of one of Opal Yellow and one of Ivory. As a result, if you are very interested in how Ivory behaves on top of Cobalt, you are going to have to try it yourself. Sorry about that!
In terms of reactions with other colours, Cobalt is not very interesting, although it is certainly nice to have some stable, non-reactive colours in our palettes. The only things I observed in these test beads are that Opal Yellow, Peace, and Copper Green all separate on top of Cobalt, and that Copper Green develops a dark patina when used with this colour.
And finally, here is the Cobalt goddess bead. She has a little lint on her, but if you ignore that, you can see the richness of this colour and the different hues it takes on depending on the thickness and how the light hits it.