Mounting adhesive is an application for attaching a graphic – a photograph, print, or poster, for example – to a board or substrate, which may be rigid or semi-rigid. While it often refers to attaching a photograph to a mounting board, it can also refer to mounting a poster on a wall, or even on a refrigerator. Mounting and laminating may take place at the same time or may be done as separate processes. Depending on the choice of mounting adhesive, the benefits of mounting may include preserving the graphic from possible wrinkling or tearing, as well as making it easier to handle and display. Special white mounting film can also increase the graphic’s opacity, which may be important if it is mounted on a dark background.
Mounting adhesive types are divided into pressure sensitive and heat-set varieties. Important characteristics to consider are tack, sheer strength, and peel strength, as well as the way the adhesive is applied. These factors can help you choose between the many mounting adhesive types available.
Tack is how sticky an adhesive is. High tack means that the mounting adhesive will grip nearly instantly, while low-tack adhesive is able to be repositioned and a good choice for layouts and other exploratory projects. The sheer strength tells you how the mounting adhesive responds to lateral stress caused by something pulling it sideways, and this directly impacts how much weight it can carry. The peel strength, on the other hand, tells how strong a bond the mounting adhesive has formed with the graphic, or in other words, how resistant the adhesive is to being peeled off the surface of the mounting board. A permanent mounting adhesive will hold more tightly, and it is more likely that the graphic will be damaged it if an attempt is made to remove it.
Pressure sensitive mounting adhesive types include film, tape, putty, foam, liquid, and spray adhesives, but mounting boards can also come prepared with adhesive. In this case, the graphic may be joined to the mounting board during the lamination process.
Film and tape are double-sided, and some kinds of film are provided with overage in their measurements in order to avoid alignment problems during application. Tape is available on rolls or in a dispenser, and film is available in sheets or on rolls. Putty is a kneadable, reusable poster adhesive for a variety of surfaces. Foam is two-sided and useful for an uneven substrate. Liquid mount can be applied with a roller, brush, or spray gun and is geared for paper and photos. Sprayable mounts range from those that provide only a temporary bond and allow repositioning, to quick-grabbing, permanent bonds.
Heat-activated mounting adhesive types include dry mount tissue, which is made for cardboard and foamboard substrates. The wider variety of pressure sensitive mounting adhesives and the fact that at least some require no special tools or machinery to use may make them worth investigating for craft applications.