Dry Mounting

Dry Mounting is the use of a dry  tissue adhesive that is activated by heat from a heat press or an iron to bond  artwork or a piece of fabric to a mounting board. The tissue is placed between  the object to be mounted and the board. A high temperature is used to liquefy  the tissue. Depending on the type of tissue used, the bonding occurs in the  press or after removal.

Dry mounting is primarily used to mount photographs, posters, and any art-work  that is water-sensitive. This system of mounting flattens the artwork to give a  clean look. It is easier, faster, and more versatile than wet mounting. The  disadvantages of dry mounting are that it is not reversible in some cases and  not easily reversible in other cases. If it is reversible, it is not reversible  in water. The high temperatures often attained in dry mounting may cause  bubbling and may prematurely age photographs as well as scorch fabrics. Dry  mounting is not generally considered an archival method of mounting.  (Photographs dry mounted to museum board are considered an exception to the rule  by some conservators of photography collections.)

Dry mounting is a rapidly changing field. There are continual improvements and  nothing should be taken for granted. The current leading supplier to the framing  industry is Seal Inc. The type of products it offers and the evolution of its  products provide us with a ground for comparison. The use of its product names  in the following discussion is for convenience and is not a product endorsement.

Fotoflat is a removable, thermoplastic adhesive tissue, which was developed more  than thirty-five years ago. It consists of a piece of thin tissue paper, which  is used as a carrier for the adhesive which has been sprayed on both sides. The  adhesive melts at 180°F to 225°F (82° to 107°C) and has the advantage of not  scorching and providing ease of removal with low heat. It bonds as it cools, at  about 150°F (66°C). The disadvantage is that mounted works exposed to the heat  of direct sunlight or left in a hot car could separate from the mounting board.

MT5 is a nonreversible (cannot be removed)  adhesive tissue used for permanent mounting. The bonding is activated between  225°F and 275°F (107°C and 135°C) and must be cooled under pressure. This tissue  overcomes the problem of accidental separation in exposure to heat. It may,  however, injure the artwork because of the high temperatures needed for the  mounting process.

ColorMount was developed to work with  resin-coated photography papers that came on the market in the 1970s. This  tissue must be used within a narrow temperature range, 195°F to 205°F (91°C to  96°C). If the temperature rises to 212°F (100°C) the moisture in the photograph  will begin to boil and the resin coating will prevent its evaporation, thus  creating blisters and bubbles. Tempera­ture-indicator strips can help check the  temperature settings.

Fusion 4000 is a newly developed thermoplastic  without a tissue carrier. It is designed to resolve the problems inherent in the  other products, which it does, but it also has some working difficulties of its  own. The adhesive tends to be a bit runny in the press when it melts. This means  that the artwork could shift position slightly, and/or some of the adhesive  could be transferred to the face of the artwork if the instructions for use of  cover sheets are not followed precisely. Bonding takes place while cooling under  pressure.

To prevent bubbling in the use of any of the  products mentioned, it has been suggested that the mounting board and artwork be  predried in the dry mount press for best results.

The attempt by 3M to deal with the multitude of  problems presented by dry mounting has resulted in a product it calls ProMount.  This product was intro­duced in 1979 for general-purpose mounting and for the  mounting of resin-coated photographs and Cibachromes. The manufacturer makes  many claims: that it may be used on a large variety of surfaces; that no hot  tacking iron is needed; that predrying is not necessary; that the adhesive is pH  neutral; that removal can be accomplished by reheating; that cooling weights and  pretrimming are not needed; and, best of all, that there is a five-minute “open  time” to reposition the artwork before cooling. It sounds marvelous, and I hope  time will confirm all these claims.

Products such as these require the reading of  all technical literature and instructions on handling. Unfortunately, most  visual artists rarely do this before proceeding. Materials like these do not  lend themselves to impulsive creativity. Small errors will probably end in large  disasters.

(Excerpt from ART HARDWARE: The Definitive Guide to  Artists’ Materials, by Steven Saitzyk © 1987)