Foamcore Boards
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(Excerpts from ART HARDWARE: The Definitive Guide to Artists’ Materials, by Steven Saitzyk © 1987) Foam boards were originally developed for use in the graphic arts, but have now found their way into the world of fine art. Foam-center boards are lightweight boards made of a rigid plastic foam with a paper or plastic facing. They resist warping, are more dimensionally stable than boards made from wood pulp, and are far less acidic. Despite the many advantages of this type of board over most paper boards, it cannot be considered archival because the core is polystyrene, or some variant of polystyrene, and this material naturally decomposes over a long period of time and is said to give off acid vapors. This aging process is greatly accelerated when exposed to ultraviolet light (some of the newer boards have UV stabilizers) and air pollution. Some manufacturers have begun to buffer the surface paper to help maintain an acid-free surface. In museum style picture framing, where foam board is used as a backing material, it is not exposed to ultraviolet light and the elements. This would make its use in framing quite safe as long as it is not in direct contact with the artwork. Unfortunately, some artists think this material is safe to use as a painting or sculpture material for fine artwork when they learn it is used in museum-style framing. Unless foam board is thoroughly covered-particularly the exposed foam edges-with enough paint to seal the surface from air and to prevent ultraviolet light exposure, it will deteriorate too rapidly for fine art. Foamcore BoardsFoamcore boards are made with a polystyrene core and either a white claycoated or brown Kraft paper facing. The original white foamcore board was produced for the graphic arts industry by Monsanto and was named Fome-Cor. Today there are several other competitors, as well as a generic version. The way the polystyrene bubbles are formed during manufacture allows the edges to stay sealed, or at least crimped, during die cutting. This creates a characteristic pillow effect. It also means that any accidental impressions or dents can permanently damage the board. The foam center is not affected by moisture, but the surface paper is, and outdoor use as well as wet mounting can be a problem. The surface will readily accept oil paints and acrylic paints, but the foam is sensitive to some solvents, particularly those in lacquers and shellacs. Fome-Cor cuts easily with a razor blade, if the blade is sharp and without defects; if it is not, it can tear the foam instead of cutting it. My experience with this particular board is that it behaves as if it had a grain and tends to cut well in only one direction. This board is commonly used in dry mounting and vacuum mounting, as well as in wet mounting when counter mounting is done. There are three types of Fome-Cor: original, acid-free, and super thick. The original is made in two thicknesses, 1/8 and 3/16 inch, and four sizes, 20"X40", 32" x40", 40"X60", and 48"X96", of which the first two are most common. In the 3/16-inch thickness, there is a greater variety of available sizes, but only the first three are readily found. The surface pH is slightly acidic, 5.5 to 6.5, and it is for this reason Monsanto produces an acid-free Fome-Cor where the surface paper is buffered to a pH of 7.5 to 8.5. The printed literature for this board suggests that it is archival and may be used as a substitute for museum board. This seems questionable because, for example, the surface of this board is made from a Kraft paper and not a purified cellulose, or cotton fiber. It is uncertain how much alkaline reserve the buffer can provide in neutralizing air pollutants and the natural formation of acid during the aging of Kraft paper. There are also questions about the permanency of polystyrene itself. This board is obviously an improvement on the original; nevertheless I have reservations about its archival qualities. The acid-free foam core is produced in thicknesses of 1/8 and 3/16-inch, and sizes of 32"X40" and 40" x60". The super thick variety, called Fome-Cor ST, is identical to the original board but is -1/8-thick instead of 3/16-inch. The available sizes are 30" x40", 32" x40", and 40" x 60". Prime-Foam-X ® BoardPrime-Foam-X is produced by Primex Plastics Corporation. With all its similarities to Fome-Cor, it has some significant differences. The outer paper facing is thicker, whiter, and glossier. The formation of the foam bubbles and their higher density in this board allow for better retention of shape and minimize damage. This board is said to have "memory" because slight indentations tend to heal themselves. Consequently, in die-cutting the edges do not crimp or seal as they do with Fome-Cor. I have found that Prime-Foam-X does not have any directional cutting resistance and cuts well in all directions. It is manufactured in the same sizes as Fome-Cor and is also available in an acid-free version. This board is now produced with a UV inhibitor to reduce the possibility of ultraviolet light breaking down the foam. There are two thicknesses-0.125 inch, or '/e inch, and 0.210 inch, which is almost 1/4-inch thick and is thus often referred to as '/a-inch nominal. Primex prefers to use thousandths of an inch rather than fractions in referring to thickness. The surface pH is between 6.5 and 7.0 for the regular surface and 7.5 for the acid-free surface. Prime-Foam-X is a little more expensive than Fome-Cor. Gatorfoam® BoardGatorfoam has a foam center of Dow styrofoam polystyrene with a Luxcell veneer. The veneer is a multilayered, resin-impregnated, Kraft paper surface. Styrofoam is a much harder form of polystyrene foam and is much more durable, but does not have any better aging properties. The hardness of the core combined with the Luxcell veneer results in a board that can only be cut with a table saw, which significantly reduces its ease for use in picture framing and storage. The major advantage of Gatorfoam is its thickness, which ranges from 3/16 to 1' inches. The 3/16, t , and 3/4-inch thicknesses are made in 30" x40" and 40"x60". One inch and 11h inches are available in 48"x96" as well. Gatorfoam is manufactured with two surfaces, one white, the other brown. The brown Kraft is better for receiving paint and for mounting. There are also two grades: Gatorfoam I is the standard, Gatorfoam II is a less expensive version with an expanded polystyrene foam center. This board is primarily used in model building and as a lightweight substitute for plywood. Gilman BoardGilman board is like Gatorfoam II in that it has an expanded polystyrene core, which is also known as block foam. The outer sheeting, however, is a claycoated, white sulfate paper. This paper allows the board to be hand cut by first scoring with a mat knife and then bending, which makes it more practical for picture framing. Gilman board is produced in thicknesses like Gatorfoam-from 3/16 to 1 inch, but only in 4'x8' sheets. ArtcoreArtcore, manufactured by the Amoco Company, is not a paper, or a paper surface foam board. It is entirely plastic. It is polystyrene foam covered with a white styrene sheet. Since it is all plastic, it is also waterproof. The surface sheet is treated with a UV inhibitor to reduce deterioration from sunlight and fluorescent light. The nonabsorbency of the styrene facing can, however, make mounting difficult. I have had areas of several photographs separate from the surface after vacuum mounting. In fact, after experimenting with this board I have found it has no advantages for framing and storage over the paper-faced foam board. It would seem more practical for making displays, models, and signs. Its surface pH is 6.0 to 6.5, and it is manufactured in thicknesses of 1/16, 1/8, and 3/16 inch. The available sizes are comparable to other foam boards. (Excerpts from ART HARDWARE: The Definitive Guide to Artists’ Materials, by Steven Saitzyk © 1987)
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