I have completed a painting of a koi carp pool, thanks to a blizzard removing the distractions of tv, telephone and internet for 24 hours. Its on a half sheet of masa which is then glued onto a half sheet of Bockingford 140lb watercolour paper. The full painting is below, and a close up of two of the fish in the top image.
The process is a little time consuming in the set up but once that is complete it's fairly straightforward in watercolour painting. However, masa paper does become quite fragile when wet, so manipulating the paint on the paper is impossible without it turning to fibres under your brush, then tearing. So painting on this makes you think carefully before you place your brush and to let layers dry throughly before adding more.
I'm working on another fishy piece using the same technique that's coming together slowly and I will give you a sneak preview of it now. You can visit my blog - Illustrated Life - over the next few days to see more and to read details on how the whole thing is created using this technique.