Silk scarves - setting paint in the sun

At last I did some of my sunpainting on silk scarves.  I had a friend around and we each made one and then I used up the excess paint to do a final one and that turned out to be my favorite.  This was the first one I made.  Black and green, with cardboard butterflies and ferns from the garden.  The other one was similar, but with pink and green..

 with the leftover paint I think I laid it on thicker and put it out into the sun while it was wetter.

 that one in fact worked the best!

 the shapes came out much clearer and I think the color is brighter.

 this is the first one finished - the ferns left an imprint but the cardboard butterflies did nothing - interesting.

 Look at the amazing detail from the plumbago flowers even though they were so light and delicate.

 I used setacolor transparent paints, and a couple of things I learned were:
put the item out in the sun asap - this makes the color brighter.
Use natural items out of the garden - not cardboard designs.
Have you done anything like this before?

I got my supplies from http://www.dharmatrading.com  - they have not given me any discounts or rewards for recommending them.  It is a great site - they have  a lot of tutorials and advice and I found there prices and delivery very satisfactory.