from days of Harvey’s [CHQ] and Edwal developers. It is seasoned developer, developers before greater knowledge of buffering the emulsion byproducts of developing. Fresh developer (777) was mixed in clear glass bottles; into this was put the butts and tails of the roll of film. After enough time, this clear became cloudy. This aged film was put into “old brown” jugs. Old brown was used as starter for “clear”

in paper terms, it doesn’t mean exhausted hydroquinone, it means chemicals from the paper emulsion intermixing with developer chems. In early days, when lith was a commercial, highly controlled procedure for making controlled dots, this could be a ‘bang’ paper such as Broivira 6. Current use of “old brown” can mean the seasoned [weaker] developer used in solarization, more likely OB means seasoned LITH developer.

These high contrast papers had cadmium, and rhodium chloride essential for high-contrast long storage paper. a darkroom would have grade 5, or 6 in stock, but likely use infrequently. These paper found their way into splashboard processes such as solarization, and lith, with lith meaning using exhausted developer from the lithographic side of the shop. These prints took on coarse clumped particles of warmtone hues, unlike lith-proof paper which remained true bowntone when processed in lith developer.

Like many specialties, photography borrows terms from existing fields. We also adapt concepts: old brown is similar to Solera:
[ Solera is a process for aging liquids such as wine, beer, vinegar, by fractional blending in such a way that the finished product is a mixture of ages, with the average age gradually increasing as the process continues over many years. The purpose of this labor-intensive process is the maintenance of a reliable style and quality of the beverage over time.Solera means “on the ground” –wikipedia]