Darkroom Tip: Keep Every Bath Within a Degree

Film emulsion swells and contracts with temperature. Move it abruptly between baths that differ by several degrees and the gelatin can micro-crack — reticulation — or produce mottled, coarse-looking grain.

The fix is easy: temper everything together. Stand your stop, fix, and a jug of wash water in the same water bath as your developer while it comes to temperature. Aim to keep the whole process within about 1°C.

Cold tap water in winter is the classic trap — mix your wash water ahead and let it sit with the rest.