Powder migration for fused glass has become quite popular recently, so here is a little set of tips and links from me.
Here is one of my first samples. This is one sheet of 3mm clear glass, with a 2mm layer of powder frit sifted on top, and then a layer of coarse clear frit placed on top. I used tweezers to move pieces around to get an even coverage. I then full fused it. The sample is approx 10x10cm.
Colours: Deep Cobalt Blue Opal Powder. Coarse Clear Powder Frit.
Other glass: 3mm Tekta clear.
Note that this piece will not come out perfectly square.
You could try adding several colours of power and then white opal coarse frit (0113) on top to make white polkadots with rainbow edges.(This would need firing for a bit longer than normal as white frit is harder to melt down).
You could use more than one colour of coarse frit.
You could try using reactive glass, for instance turquoise blue transparent with french vanilla opal, which would give you halos around your dots. You could do this either way round!
You could try doing this on an opal background.
You could try putting silver on top of your base glass, then a non-reactive powder, and then coarse frit which would react with the silver.
Check the Bullseye reaction chart for more ideas and inspiration: http://www.bullseyeglass.com/methods-ideas/get-a-reaction-bullseye-reactive-glasses.html
The sky's the limit! I'd love to see what you create - please do post them in the comments :)
Resources and links:
This little tip from Warm Glass USA gives the basics: http://www.warmtips.com/20060530.htm
This pinterest board focuses on powder migration and reactive glass pendants, so is a great place to look for inspiration: https://uk.pinterest.com/cdnrebel/powder-migrationreactive-glass-pendants/?etslf=4915&eq=powder%20migration
Another interesting tutorial is the River Rock Reaction: http://www.bullseyeglass.com/methods-ideas/river-rock-reaction.html
If you are looking for a tutorial in more depth, then you could buy "The Pebble Experience" webinar DVD by Tanya Veit of AAE Glass. She starts off with powder migration techniques, and then moves on to her pebble technique. She also has a great set of colour combinations for Bullseye glass. (Note: Buying this DVD does not give you access to her pebble experience Facebook group.)
If you are looking for a book, try "Contemporary Fused Glass" by Brad Walker, which has a chapter on this and is also a great resource.
Disclaimer: Use these tips at your own risk. Always wear appropriate eye protection and use a proper breathing mask when working with powders. Happy fusing!
Experienced silk painter, glass fuser, teacher, enthusiastic and inspirational.