I have made a seamless pattern from these elements. The elements rely on solid white fill in order that they overlay without showing through. However, I need to make a transparent PNG file of the pattern for use in a website. So far I have not figured out a way to do this. Any help gratefully received (p.s. I'm fairly new to Illustrator).
Making opaque areas (or any other color in fact) transparent is pretty easy:
You can then proceed remaking it into a pattern.
Image 1: Screenshot after procedure, green box in background show effect (and grid too)
An alternative method is using a little known feature in illustrator:
You now have mostly the same but haven't needed to expand the shape which means you could affect line thickness etc.
Image 2: Showing method 2. with rings selected to show that they in fact are intact
Again you can go ahead and make a pattern out of this shape