Recently I was having a play around creating surfaces and I added some kitchen tin foil to the surface of the calico, but it wouldn't play nicely so I covered it with tissue paper and carried on painting, once dry I liked the subtle effect where the foil showed through the tissue even with the colour on top it left a glow.
I tried out some larger pieces, using a base of calico I covered it with pva glue and then tin foil, you can push little creases in if you wish at this stage, I didn't want too many, I then covered the tin foil in pva glue and scrunched up my tissue paper and laid it on the top and allowed to dry. It takes a day or so.
I then just built up washes of colour with Goldens fluid acrylic (magenta) and interference oxide violet and green.
The one below I scrunched the foil up a bit more then added the paint while everything was still wet, and it came out the same as the first sample. Although you can't see the foil there is a lovely sheen to the base colour