Here’s the next part in my Roving Reporter posts. Raku Glass.
Huh? Isn’t raku a ceramic/clay process? Well, yes. Raku ‘glass’ is actually stock number R108 (made by Reichenbach in Germany) but the effects you can get resemble pottery raku effects. R108 is actually Reichenbach iris orange and was sold as a furnace glass color.
A few years ago (at least) Val Cox introduced the frit version in smaller quantities to us lampworkers with the name of Raku Jitterbug. She began to show us the really cool effects and people went nuts. Well, I know I did.
Raku frit has been sold in multiple sizes and also more recently in cane form and shards for lampworkers. (Don’t get the Rod form as it’s about 1.5″ in diameter and meant for the furnace people).
Raku frit of the Reichenbach variety is 91-94 coe. This means that it is only compatible with most soft glass (104 c0e) in small quantities.
So, what does it do? This brown looking glass, when heated really hot and then cooled, turns beautiful variations of blues, purples, maroons, tans and everything inbetween. When reduced (held in a propane rich flame) it gets a metallic sheen.
To pull out the colors I’ve found that it is best to ‘super heat’ it until it almost goes clear and then touch it with some kind of tool or surface or blow on it with a strong burst of air. When Raku first made its debut there were many debates about the best cooling methods. Some people insisted that the tool had to be brass. Others insisted that you needed the brass to be iced. I have found that just touching with a graphite marver is sufficient. As is blowing strong puffs of air onto the super heated bead.
The bead above shows the R108 in two different applications. Around the edges is frit that has been applied. You can see some of the burgundies, purples and tan. The dots were applied with stringer, flattened with a graphite marver and then capped with clear glass.
I haven’t worked too much with Raku in stringer form but there are some amazing things being done that way. Here is a post by Dawn Scannell called The Secrets of Raku Revealed on Lampwork Etc. That should give you plenty to go on!
See more beads like the one above at: lorigreenberg.com