Before wet packing - always rinse them several times to remove the fines that are left behind in the processing. These un-dersirables will give your opalescents a cloudy not translucent effect.

Also, many opalescents become more milky the longer you fire them (still talking about very moderate fires here), so for maximum control of the intensity of the opalescence, the fires have to be very careful and checked often. The technique of Nouveau Grisaille developed by Andreu Vilasís takes maximum profit of this effect, with opalescence control and thickness of layer to achieve different shades and volumes. See wondeful works here: http://focgallery.com/SXXI.aspx The only opalescent I personally know that becomes transparent with overfiring (probably because I haven't tried overfiring any other) is Schauer 64. But the opaqueness (this one is almost opaque white, but with a porcelain translucency) in this one comes back if it is fired again, very forgiving.

I emailed Thompson with a question about opalescent lumps and they replied with this link: http://www.glass-on-metal.com/pastart/Opalescentenamel.htm It is a great description of how to fire their enamels. It must be what I read somewhere in the past about firing opalescent high to transparent then re-fire low to get the opalescent effect. Jim

Oh my god, thank you Jim,

this will be so helpful to everyone!!

Thank you so much for this info. I am so excited to try out my Opalescent Colors (the ones from Thompson). This is going to be fun!