folded from a 50 cm square of double-layered watercolour paper.
Using two layers of paper is a simple solution when wet-folding models that use colour-changes. You do not have to join the two pieces of paper in any way (using gl*e); simply lay them on top of each other and start to fold.
diagrams from
Proceedings of the
Spring Convention Birmingham 1998.
British Origami Society, 1998.