Art papers

Watercolour Papers
Watercolour paper has a “hard size” on top of the paper that allows the water to penetrate and the pigment to remain on the surface. This gives the painting its brilliance and also allows for corrections.
Watercolour paper comes in different textures. ‘Hot Press’ (HP) is the smoothest, it is also a bit less absorbent as it has ben compressed to a harder surface. ‘Not’ (also called cold pressed) has a medium textured surface and is the most popular finish, it is especially good for beginners. ‘Rough’ is highly textured paper and is the most absorbent. Botanical artists often prefer hot pressed paper as the smoothness allows them to be very accurate in their rendering.
The weights of the papers range from 90 lb to 400 lb. The heavier the weight of the watercolour paper the less the paper will buckle when wet. For lighter weight papers (140lb and below) the paper is usually stretched (wetted and laid out on a board and taped down with gum-strip tape, or you can use a specially designed paper stretcher device like the Keba Artmate).
Watercolour papers can vary in whiteness from bright white to a creamy off-white and are available in tinted colours.
Watercolour papers come in sheets, pads, rolls, and blocks. Blocks are pads of pre-stretched paper that are glued on all four sides except for a small space on one side. This allows for painting without stretching and when the painting is dry you can remove the top painted sheet by running a butter knife around the edge from the gap in the side.

Drawing Papers
Cartridge paper is a high quality type of heavy paper used for illustration and drawing. It comes in a variety of smooth textures. It is available in loose sheets, pads (glued or spiral), hardbound and softbound sketchbooks and rolls.
Bristol paper is a strong and durable, all-purpose drawing paper. It has a very hard surface that is heavily sized, polished, and compressed. It is also used for airbrushing.
Other papers that are suitable for drawing include the very popular Stonehenge paper.

Pastel Papers
Pastel paper is used for soft and hard pastels and charcoal. It is usually coloured paper, with the colour chosen being very important as it will be a major component of the finished work. It comes in a few different textures, all with some amount of tooth or weave that will catch hold of the pastel particles. Ingres is a laid paper with a mesh imprint from a screen. Random texture gets its surface from a cloth matt imprint, similar to Not texture watercolour paper. There are a few types with toothy textures from ground cork or sand that are similar to sandpaper. A few come with the colour screenprinted on and some are waterproof for working the pastels with water.
Paper for oil pastels is hard and white and usually comes in a pad with glassine paper interleaving to protect it from smudging.

Oil and Acrylic Painting Papers
These medium to heavyweight papers are usually canvas textured and primed for painting with either oil or acrylic. Most of the papers prepared for acrylic paint are universally primed to accept both oil and acrylic. Paper must be sealed completely if painting with oil paints because the oil will separate out if the paper is absorbent and form a halo of oil around the colours and it will also rot the paper over time. Although acrylic paint can be used on any paper, acrylic painting paper is usually designed to mimic canvas or it is very heavyweight. Oil and acrylic painting papers are especially useful for taking to classes or using in the field and are an economical choice for making a study or sketch prior to the major work on canvas.
You can also get sheets of primed actual canvas (as opposed to the canvas-textured paper) in pads.

Fine Art Digital Papers
Inkjet papers that allow high quality reproductions of your artwork or prints of your digitally designed original prints come in a wide variety of textures and weights. They are coated to accept inkjet inks. They can be sprayed with an inkjet fixative to prevent smudging if that is a problem. They are archival. Sheets of primed canvas designed to go through your inkjet printer are also available.