JAIC 1981, Volume 21, Number 1, Article 3 (pp. 49 to 64)
JAIC online
Journal of the American Institute for Conservation
JAIC 1981, Volume 21, Number 1, Article 3 (pp. 49 to 64)


Henry Wilhelm


THREE PATCHES, EACH about 1.3 cm 3.3 cm ( 1 inches), should be prepared using print material, processing chemicals, and processing procedures identical to those used with the original print. Any variation from the processing chemicals or procedures used with the original print may affect the fading characteristics of the monitor and may reduce its accuracy. One patch should be minimum density (white); one patch should be a neutral gray of about 0.35 density; one patch should be maximum density (black). Ideally the patches should be printed on the border area of each original print when it is made. However, it is unlikely that this will become common practice, and the patches will usually have to be optically printed in the proper size on a single sheet of print material. As an alternative, entire sheets of material can be printed to the desired density and the sheets cut into the proper size after processing.

The three patches should be mounted on the same type of board used to mount the photograph being monitored and should be attached with the same type of adhesive or mounting system (Fig. 3). When it is used, the monitor should be covered with a matte made of the same type of board as that used to overmatte and support the original print. The overmatte should have an opening in the center, and only one-half of each patch should be exposed to light, so that the light-fading and dark-fading functions of the monitor are separated (the overmatte must be essentially opaque to light if the monitor is to give an accurate indication of dark-fading). The monitor should then be placed in a small frame13 using the same type of glass or plastic covering and backing materials that were used with the original print to which the monitor has been assigned (Fig. 4).

Fig. 3. Fading monitor with overmatte. The three pieces of color print material are mounted on the upper center of the board; the mount board and overmatte measure 6.4 8.9 cm (2 3 inches).

Fig. 4. Fading monitor covered with sheet of glass in small metal frame.

Copyright 1981 American Institute of Historic and Artistic Works