But, just to make watercolor even more fun, there are also other types of supports.
Yupo: is not really a paper but a synthetic sheet with a very slick surface.
You get lots of chances here to be 'loose'. Some artists have mastered the paper to create very detailed paintings but generally it is good for loosening things up in a more free flowing style.
The surface is very slick and allows the paint to flow over the surface until the water evaporates. Colors can be built up but it is more difficult to glaze color.
Some good demos can be found:
This is just an explanation of the paper:https://www.youtube.com/watch?v=SsFursDk2e0