There are three different watercolour papers in general use as far as surface finish is concerned.

1. Hot Press - smooth surface
2. Cold Press or NOT - medium rough surface
3. Rough - very rough and distinct surface

Each paper surface is suited to different watercolour techniques and types of painting. The most popular surface finish is cold press as it will support a good level of detail but also offers the ability to use dry brush techniques where the surface is used to break up the application of paint.

Rough for some people takes a bit of getting used to and the actual roughness of the paper finish depends on the paper manufacturer. Its surface lends itself to the painting of landscapes so that the texture of the paper can be used to create the effect of foliage, hills and mountains and the surface of water much more easily than you can with cold press.

You can purchase watercolour paper in single sheets, a pad of sheets glued on the top edge or a block of paper.

If you purchase a watercolour block, this is a pad of watercolour paper that is gummed on all 4 sides. A small gap in the glue on one side that allows a palette knife or credit card to be inserted and used to remove the top sheet once you have fininshed your painting. The benefit of a block is that the paper is less prone to cockling simply because it is glued on all 4 sides during manufacture.

Here are 3 images, which were very difficult to take, to try and illustrate the actual surface finish of each paper.

Each of these different paper surfaces come in various weights paper again depending on the manufacturer. The most used weight of paper for watercolour is 300 gsm or 140 lb.

If watercolour paper is less than 300 gsm then it will be very prone to "cockling" if a lot of water is applied to it. 300 gsm can also cockle fairly easily if you are using the wet in wet technique. I explain in another tip how to avoid the "cockling" problem by stretching your paper before you apply watercolour paint.

You can obtain heavier weights of watercolour paper, 425 gsm (200 lb) or 600 gsm (300 lb). These weights of paper do not necessarily need to be stretched to prevent cockling, especially the 600 gsm paper.