Matting

A mat serves to protect a picture, whether framed or stored, and to enhance its aesthetic qualities. Since the mat is in close contact with the picture, the collector and framer should be particularly careful about the quality of the materials used in its manufacture. False economy leads many inexperienced framers to use wood-pulp matting board, which is acidic and contains a high percentage of unrefined groundwood pulp that inevitably disintegrates. The picture absorbs some of the destructive chemicals and becomes stained. Mat board of this type is usually faced on both sides with a paper of better quality [even pure rag stock may be used] to make the discoloration less apparent. When an opening for the picture is cut, however, the inner core of inferior material is exposed, and the corrosive chemicals soon migrate into the picture. Pictures that have been kept in such a mat for just a few years begin to show a characteristic brown stain that corresponds with the inner edge of the mat opening [Figure 5].

The only safe matting board now available is "museum board," called all-rag matting board, which is composed not of actual rags but of high-grade cellulose obtained from cotton fibers. It is acid-free and most frequently manufactured in white and off-white, although it is now available in a few colors. It can be obtained in three thicknesses: 2-ply [1/32 in. approx.], 4-ply [1/16 in.], and 8-ply [1/8 in.]. The first is helpful where there is a lack of storage space, but it should be used only for pictures whose value is not particularly great. The 4-ply thickness is the one in most general use and provides an adequate depth to allow for minor buckling of the picture or the relief qualities of some woodcuts, as well as sufficient "breathing space" between the glass and the picture if it is framed. For pastels, collages, and especially large pictures like contemporary lithographs, the 8-ply thickness is recommended. One may substitute two sheets of 4-ply, which are somewhat easier to cut and are less expensive than the single sheet of 8-ply.

Museum board is usually sold in quantities of twenty-five sheets measuring 30 [or 32] by 40 inches, but some of the larger art supplies stores sell smaller quantities to customers interested in cutting their own mats. Mats can also be improvised out of heavyweight, hot-pressed watercolor paper. [p. 25]

The basic window mat [see Figure 6] consists simply of two pieces of mat board hinged together with a strip of gummed cloth tape. A well-proportioned mat should reflect the dimensions of the picture, and its lower margin should be slightly greater than the upper. If placed directly in the mathematical center of the mat, the picture will appear to be just below center, so that a wider bottom margin is needed as compensation. A space of at least 1/8 inch should be allowed around all sides of the image or plate mark. This is particularly important for a print without margins, since, if too little tolerance is allowed, the edges of the print may be damaged when the mat is opened and closed.

The only essential tools for cutting a mat opening are a straightedge made of tough material and a sharp knife, easily obtainable in most art supplies stores. Various devices ranging in price from about five to nearly three hundred dollars are supposed to make it possible for a beginner to cut a professional-looking opening. They perhaps have their place, but for simplicity and versatility the ordinary mat knife, combined with practice, is hard to improve upon.

The difficulty most frequently encountered by those using a mat knife for the first time stems from the tendency to try to cut through the board in one stroke. This tires the arm quickly and makes control of the blade more difficult. Use a light, even pressure and concentrate on keeping the angle of the knife constant. At first, three or four strokes may be necessary to cut through a four-ply thickness, but after some practice only two will be needed, one to make an initial scoring and another, firmer cut to finish. The knife should be held at an angle so as to make a beveled edge around the opening, which is more pleasing visually than an abrupt ninety-degree cut. After the opening is made, the beveled edge itself will be almost knife-sharp and should be lightly sanded to prevent possible damage to the picture. The sharpness of the outer edges of the mat should also be reduced by light sanding or by running the back of the knife along them, especially if the mat is to be kept unframed as part of a study collection. The mat is then more agreeable to handle and less likely to scratch or abrade the surface of another picture if accidently dragged across it.

Hold the picture in position in the mat by attaching it to the backboard, not the front, with two hinges affixed to the upper edge of the reverse side of the picture [see Figures 7 and 8]. Never paste the corners of a picture directly to the backboard. Hinging allows the picture to hang freely in the mat and permits the paper to expand or contract without stress as the atmospheric conditions vary. If the picture is likely to be transferred from one mat to [p. 26] another, the picture can be hinged to a sheet of rag paper, which in turn is attached to the backboard. When attaching a picture to its mat never use pressure-sensitive tapes of any kind [masking tape, scotch tape, etc.], gummed brown wrapping tape, synthetic glues, or rubber cement. Use instead a good quality gummed paper or a Japanese paper applied with starch paste.

Gummed paper may be cut in strips one-half inch in width, of whatever length is demanded by the size and weight of the picture to be supported. The strips are folded in half and applied first to the picture and then to the backboard. For especially large pictures [e.g., contemporary graphics] use short lengths of gummed cloth tape, which is stronger than paper. Gummed paper or cloth hinges are simple and quick to use, can be removed easily, and are less dangerous in the hands of an inexperienced worker than hinges that must be applied with paste. Hinges made of Japanese paper take more time and practice to apply. Select a Japanese paper whose weight matches the picture, and do not apply the paste too thickly or the picture will buckle around the hinge. After attaching the hinges, cover them with blotting paper held down by a light weight for a few hours until they are dry.

The best adhesive for hinges is made from starch, preferably wheat or rice. In a two-quart double boiler put four and one-half cups of cold water and one cup of starch. Let it stand for a few minutes to allow the starch to become thoroughly wet. Cook over barely simmering water for twenty to twenty-five minutes, stirring frequently. When ready, it will be thick and opalescent and will be filled with minute air bubbles. At this point one teaspoon of a ten percent solution of thymol in alcohol may be stirred in; this will preserve the paste for weeks if kept covered. Cool by placing the top of the double boiler in a bath of cold water, stirring the paste frequently to prevent the formation of lumps. [For further details see Anne f. Clapp, Curatorial Care of Works of Art on Paper, Oberlin, 1974, and Roy Perkinson, Conserving Works of Art on Paper, Washington, D.C., 1977.]

A hinge should not be wider than necessary for satisfactory adhesion. To keep a picture from slipping in the mat, the length of a hinge, measured along the upper edge of the picture, is more important than its width. It is sometimes said that the hinging paper should be weaker than the picture so that it would give way first if the picture were put under strain, but this requirement cannot be fulfilled in practice. Experience has shown that a picture is more likely to incur damage because of hinges that are too weak rather than too strong. Hinges must be able to withstand the shock of accidental rough handling or dropping of the mat or frame. [p. 29]

Museum board is not now available in the same variety of colors and textures as the inferior wood-pulp types. A colored or decorated mat may be made either by covering the all-rag mat with a high-quality paper of the desired color and texture or by coloring the mat itself. If for some exceptional reason a wood-pulp mat already on the picture has to be saved [if it bears the artist's signature, for example], it can be placed on top of a mat made of all-rag board.

Choosing the color and design of the mat can be either an enjoyable experience or one of utter frustration, depending on the individual. A good rule to follow for both the amateur and professional framer is that a picture should not have to compete for attention with its surroundings. This does not mean, however, that the basic colors in the picture should be repeated in the mat. The glowing brown tones of a bistre drawing, for example, lose their effect if surrounded with a mat of a tan or umber tone. A cool slate blue or olive gray provides a visual complement to the color of the drawing and enhances its appearance. Using complementary colors in this manner is often the key to presenting a picture with its full aesthetic effect.

As a general rule, the off-white color of the all-rag matting board is sufficient for etchings and engravings. Simple, colored mats look well on watercolors, and mats more elaborately decorated with color, ruled lines, and perhaps a narrow strip of gold paper ["French mats"] are often effective on drawings. Bear in mind that the simplicity of a mat's appearance is the key to continued enjoyment of the picture.

Several matted pictures can be stored conveniently in wooden drawers or solander boxes, which are the traditional container for matted pictures. This type of box opens out flat, forming a convenient temporary tray, and permits easy access to mats stored within. Large pictures and maps [up to approximately 30 by 40 inches] may be kept matted and in acid-free folders, but in the case of oversize posters and prints individual solutions have to be devised. [p. 30]