UP-5 paper developer

Description

The UP-5 universal developer: a warmer tone on papers inclined that way, and slightly softer contrast than ST-1. Supplied as a ready working solution.

What the warmer tone comes from

A formula with less hydroquinone activity develops finer silver particles, and fine silver looks warmer — brown rather than neutral black. The effect is clear on chlorobromide and warm-tone papers and weaker on neutral bromide ones.

When to use it

Portraits, landscape, any print that should step away from cold neutrality. For the coldest possible black, take D-72.

Questions and answers

Can tone be controlled by dilution?

Within limits: a weaker dilution and longer development usually reads slightly warmer. The paper still decides most of it.