For outdoor painting it will not always be convenient to stretch lots of sheets of paper. For this it is advisable to buy boards with paper already fixed to them.
You can get Whatman boards in the three grades, Fashion-plate boards also in three grades, and a strong board-like paper called Green’s Pasteless boards which are very useful for oil or watercolor and can be painted on either side. All these
can be bought at any artists’ supply store and come in Imperial or Half Imperial sizes.
Sketching blocks are sheets of paper packed so that you can tear off a painting when it is finished and a fresh piece is ready for you. It is firmly secured all round the edges and in theory should act like a piece of stretched paper, but I have found that this is not so. It cockles very badly and stays cockled when dry. Also, it is very easy to rip the top paper off too quickly and tear your painting. Not recommended.
Bristol board is a very smooth, bluish tinted thin board that I have enjoyed working on with opaque watercolor. It is excellent for fine detail work and does not need stretching.
Remedying a Greasy Surface
Most rough watercolor papers have a tendency to repel the first washes of color you put on them. Therefore you can dampen them a little before painting. Usually stretching them will take off most of the greasiness from the surface but if this should persist, add a little detergent to your water. This seems to cure the trouble quite well. An alternative method is to add a few drops of ammonia to your water.
Of all brushes, sables are the most successful for use with watercolor. You can get squirrel and ox-ear hair brushes, but you cannot better a good sable brush. The sizes vary with different manufacturers but as a rough guide, 4, 8 and 12 are good sizes to begin with. These should be the ordinary round pointed brushes, not the long or square topped variety.
They should possess a springiness and when dipped in water and flicked dry retain a sharp point. If the point spreads it is not a good brush and should be avoided. Don’t be afraid of trying out this maneuver in the shop. It is common practice to do so and a jar of water is usually put out on the counter for this purpose (Fig. 14).