Favrile/Peacock Question
 

I understand what chemical to use (and how to use it) to get the iridized effect on glass. What I am still not clear on is what gives you the swirls and lines in iridized glass. Do you have to make a piece out of two or more colors and do some raking or something? Do some colors of glass take the iridizing differently, giving you the variations?

Here's what I'm talking about:

Wow, that's gorgeous! Just had to say "wow" :lol:

I don't have an answer to your question, but I suspect you're right - it might work something like the Silver Tracery Effect posted on some forums, including the ISGB forum, by Jim Smircich. I'll be watching to see if you get any more definitive answers.

I wonder if the piece was lightly sandblasted with that image before the irridizing was done?

Yes, different colors take the irridizing differently. I think it was either trailed or a striped ribbon cane(s) were applied and then raked. Since it is a blown piece, trailing is more likely.