This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Artistic Mounting. The mount must be one that will not detract from the print. On the contrary it should be subordinate to it. From this it will be understood that the use of fancy mounts should be avoided. As it is seldom that the numerous styles of stock mounts on the market will fit the trimmed print, it is usually advisable to make one's own mounts, or purchase those without set openings, so that any print within reasonable limits can be used upon them. Each print will require special consideration both as to final color and shape of the mount.
1233. There are three vital reasons for mounting a picture: First, to aid the enlargement of the print without damage; second, to isolate the print from its surroundings, and third, to enhance the artistic value of the print. The right mount will answer all three of these requirements. A mount must not be used for its own value, but for the artistic aid it lends the picture. For this reason a plain mount, void of fancy designs or colors, should be employed.
Shape Of Mount. The shape of the mount depends entirely upon the shape of the print. An oblong print should have an oblong mount; an upright panel shape print should be placed on an upright panel shape mount; a square print on a square mount, etc. Ovals, circles and ellipses should be sparingly employed, as there are few subjects that a rectangular shaped mount does not suit better. The amount of space at the top and sides of the picture may be equal, with wider space left at the bottom. If a print is mounted in the dead center of the mount, it will appear as if mounted just below the center. If a title or signature is placed under this the optical illusion is still greater, and gives the picture the appearance of falling from the mount.
Size Of Mount. The size of the mount also depends, to a great extent, upon the size of the print. A 4 1/4 x 6 1/2 print may be very suitably placed upon an 8 x 10 mount, with other sizes in proportion. Of course a hard and fast rule cannot be laid down, as it depends wholly upon the results aimed for. Generally, prints of large subjects, such as full size heads, will permit the employment of much larger mounts, in proportion, than will prints in which the objects are small. Avoid extremes. If too large a mount is used the print will be lost, while a cramped appearance will be given if the mount is too small. The final decision must be governed by your individual taste, together with occasional study of the work of artist photographers. The studies in this, and other volumes of this library, present many excellent examples of artistic mounting.
Color Of Mounts. To a certain extent the color of the mount to employ must be left to your own judgment. Before commencing work on a mount, lay the print on one color, then on another, until it appears to best advantage. A light print will appear still lighter if placed on a dark mount and a dark print will look darker if laid on a light mount. The eye is deceived, but you can turn this deception to practical account. If you think a certain print would be improved if it were lighter, mount it on a dark mount. If a print tends towards lightness, place it on a light mount and it will gain strength. Harmony is the keynote of mounting. Violent contrasts must be avoided. A warm print should not be placed on a cold toned mount. For example: A sepia print would look entirely out of place on a gray or bluish mount, and conversely a cold tone should be placed on a cold tone mount; that is, a black print on a black, or gray, mount. White, being a neutral tint, may be used frequently for either a warm or cold toned picture.