Where to begin concerning papers? Here are the basics of watercolor papers and other kinds of paper 101:
Traditionally watercolor paper is indicated by the number of pounds in a ream such as 500 sheets 22 x 30 inches. The weight of paper varies from 70 pounds [thin thickness], medium weight/thickness [ 140 lbs.] to heavier 300 lbs. to even 400 lbs. The more serious of an artist and want portfolio quality results then I suggest using a heavier weight paper. Watercolor is usually white to allow the light to reflect through the paint and bounce back out to help the transparency effect.
Watercolor paper is heavier than ordinary drawing papers and the heavier paper will receive a better amount of water and the better the paper will react. Paper can be bought in single sheets, watercolor blocks and tablets. Illustration board will hold tight watercolor or controlled realism. There are aqua boards out there that have the paper sized [glued] to the surface of the board. I have ever seen cold press paper with a tooth to the surface. Which will work well for pastels and charcoals.
There are different surfaces of watercolor paper; Hot pressed which equals the smoothest surface and less absorbent used for tighter realism in details. Hot press means the paper is made using hot water. Cold press paper has a rougher, bumpy surface made using cold water. Rough watercolor paper has a pitted surface with a pitted texture surface. Paint will settle in the wells of the paper; used for expressionistic and or “The watercolor painterly look” so many think watercolor can only do. Paper that is under 300 lbs. is usually soaked before using which means you soak the paper in water before using, stretched and taped to a board or even stapled down. Let dry before painting.
The watercolor blocks means the paper has been pre-glued together by the edges and there is an opening at the top where you can peel the sheet apart from the block when finished with a palette knife. Blocks are fairly easy to use and do cost a little more than one sheet of paper. Expect to spend about $50. to & $60.00 for 11 x 14-17 inch size block of 12 -20 sheets of paper. They do come in different weights, hot and cold press also found on most Art stores.
Rag paper refers to 100% rag cotton content and can be found in varying weights. Sizing is added either to the pulp and or surface to add level of absorbency.
When starting out in watercolor buy at least 140 lb. paper, if you buy cheap paper the water is more likely to ripple the paper becoming very frustrating making you not want to continue.
Oil paint surfaces: You can paint on just about any surface. Most choose a canvas or canvas board. You can paint on a sized with gesso masonite broad which works well. A material canvas stretched over a wooden frame should also be cover in gesso. Remember to stretch the canvas very tightly over the frame because the canvas will give on the frame when painting. Also keep in mind the surface will give or move when painting, if this seems to bother you then pick a hard gesso surface.
Illustrations boards are usually 2 ply which has a thickness of about 1/8th of an inch. Fairly smooth surface to work on and holds tight watercolor, color pencil and graphite very well. Look for a name brand to buy. One sheet sized is about 18 x 24, 22 x 26 inches and will cost in the neighborhood of ten dollars per sheet.
Matt boards come in 2, 4, 6 and higher ply thickness. Matt boards can handle watercolor if rag quality and most mediums. Oils will stain and spread once dry, I don’t recommend matt for oils.
Pastel papers are sanded, you need a rough surface for the pastels to hold onto. Pastel papers come in colors and thickness of sanded surface.
Drawing papers come in a wide range of styles from a rougher surface to smooth. I prefer a smoother surface but not without some soft tooth. This surface works well for pen and ink as well.
NOW this is IMPORTANT! ………….If you are an “Over-doodler” which means your sketches turn into more [a possible portfolio piece] on Cheap paper of 140 lb or less than you are wasting your time. These sketches turned drawings are wasted not being on good paper.