A Simplified Variable-Density Sound Negative Developer

Paul Zeff, S. J. Twining

A variable-density sound negative developer composed of Metol, borax, and sulfite is described. That such a sound negative developer is possible, is shown by a preliminary survey of the literature pertaining to hydroquinone-Metol activity at low pH values. In a developer so constituted and coupled with an adequate replenisher system, the oxidation factor is practically negligible and results in a stable pH value which in turn permits the elimination of the usual buffering agents. The value of such a developer is that it permits greater simplicity of chemical control and results in some economy. — Sensitometric data obtained from the operation of this developer show a negative H and D characteristic of maximum linear latitude, and normal printing characteristics. Gamma-density relationship is very stable during continuous negative developing runs, thus making possible quantity production of sound negatives of uniform density.

Print ISSN
Published
1944-05
Content type
Original Research
DOI
10.5594/J08447