Papers

Wood-pulp paper, which is paper in its most common form, becomes brittle and brownish with age, as evidenced by newspaper [p. 148] and newsprint pads. But age-deterioration is not produced by the wood pulp per se; it is the chemicals, particularly acids, that are the cause; witness the Oriental papers which are of wood or vegetable fiber origin. Modern wood-pulp papers are made that are sufficiently permanent for art, book, and many other uses; the paper should be certified as being free from stand acid effects. The chemists designate neutral paper as pH 6.5 to pH 7, at which reading a paper will be permanent. Conservators now frequently save decrepit works on paper by a process of de-acidification. But most artists are still limited to 100 percent pure rag paper. Perhaps in the near future standards will be adopted so that the consumer can identify good, permanent paper, other than that of 100 percent rag content. This would be an important improvement, especially in the case of such items as sketchbooks, which for the past 135 years or so have been made of nonpermanent wood-pulp paper that embrittles and turns brown within a few years--under one's own eyes, one might say. For the present, 100 percent rag paper is the artists' only option for sketchbook paper that will remain in good condition over the years.

The standard method of painting on the thinner grades of watercolor [most widely used] is to stretch the paper on a drawing board by first wetting it in a tub of water, then blotting off the surplus water and adhering it to the board with the regular brown gummed-paper tape that is sold for sealing parcels. A strip of this tape along each edge will hold the paper securely; as it dries it stretches perfectly flat and will take wetting by watercolor paints and washes without the resultant curling, buckling, and wrinkling that a loose sheet would display. Gummed tape is an improvement introduced about the 1920s; before that, white paste was used, applied about 1/2 inch in all around the edges; the gummed strips are simply more convenient. Some experience with any particular kind of paper will indicate how wet it should be; the stretching of a paper soaked too heavily may tear it at the corners, and if insufficiently wet it may wrinkle.

Most watercolor paper is sold in the "imperial" size, the sheets measuring about 22 by 30 inches. High-grade watercolor paper is also sold in blocks [pads], but not in very large sizes. Watercolor paper is priced according to its weight, which is indicated by pound numbers that refer to the weight of a ream [500 sheets]. The lightest is called 72 pound, the next lightweight kind is 140 pound, [p. 149] twice as heavy and twice as expensive. The very heavy papers designated 300 to 400 pound are really superb; they do not require stretching [they could almost be called cardboard; it is possible to paint on the paper holding it in one's lap]. They withstand much more drastic treatment than the lightweight varieties do; scraping and other manipulations that would ruin these can be done on 140-pound paper. Their prices are high, but a professional painter can consider this a normal expense if only an occasional watercolor is sold.

Most of the best watercolor paper is imported from Europe; few mass-produced American papers approach their quality. In recent years, however, individual craftsmen have set up facilities to produce handmade paper in small-scale limited production. The texture of watercolor paper varies a little with each maker; the most popular finishes in creative painting are the coarser ones, known as rough [R], or not-pressed [NP], and the least coarse as hot-pressed [HP]. The smoother kinds are co d-pressed [CP] and are occasionally used in techniques other than normal watercolor, but their principal use is for pen drawing and other techniques. [pp. 148-150]