A mount is a frame, backing, or enclosing structure used to support, protect, display, and present photographic prints and transparencies in a manner that enhances their visual impact, facilitates their handling without risk of damage, and ensures their long term physical preservation. Mounting is an important final stage in the presentation of finished photographic work, whether for gallery exhibition, client presentation, portfolio display, framing, or archival storage, and the choice of mounting method, materials, and style has a significant influence on the overall appearance and perceived quality of the presented image.
For photographic prints, mounting typically involves adhering or otherwise securing the print to a rigid or semi rigid backing board that prevents the print from curling, creasing, or buckling, and provides a stable, flat surface from which the image can be displayed or framed. Window mounts - also known as overmattes or passepartouts - are a particularly widely used form of print presentation, consisting of a carefully cut card or board with a precisely sized rectangular aperture through which the image is viewed, with the border of the mount creating a clean, neutral frame around the image that separates it visually from its surroundings and draws the eye into the picture. The colour, thickness, and proportions of the window mount border are important aesthetic considerations that can significantly enhance or detract from the visual presentation of the print.
Archival quality mounting materials - acid free and lignin free boards, pH neutral adhesives, and conservation grade enclosures - are essential for the long term preservation of photographic prints, as acidic or chemically reactive mounting materials can cause irreversible yellowing, staining, and deterioration of the print over time. Conservation mounting techniques such as hinge mounting and corner pocket mounting, which attach the print to its backing without the use of adhesive on the print surface itself, allow the print to be removed from the mount at a later date without damage and are the preferred approach for archival and fine art print preservation.
For transparencies and slides, mounting typically refers to the enclosure of the processed film within a protective frame - made from card, plastic, or metal - that holds the film flat, protects its edges and surfaces from damage during handling and projection, and allows it to be loaded into a slide projector or viewed on a lightbox. Glass mounts, which sandwich the transparency between two pieces of optically clear glass within the frame, provide additional protection for the film surface and help to keep the transparency perfectly flat during projection, preventing the image from shifting out of focus as the film expands with the heat of the projector lamp.