Ilford FP4 Plus Process Control Strips 35x100ft

Ilford FP4 Plus Process Control Strips 35x100ft

A process control system works by keeping all possible photographic variables constant, except for the processing itself. The film strip is exposed to a series of controlled exposures and then processed to create a reference. When similarly prepared films are subsequently processed, any differences between these films and the reference strip reflect the changes that have occurred in the processing system.

The strips are suitable for use with all mechanical black-and-white film processing systems that use liquid reservoirs, such as dip-and-dunk (hanger), roller transport, short leader, continuous processing systems, and manual deep tank systems.

FP4 PLUS process control strips are supplied in lengths of 30.5 m (100 ft) of 35 mm film, rolled with the emulsion inwards (EI). Each strip is approximately 41 cm long, resulting in approximately 72 usable strips per roll. The film features notches along the edge and perforations along the entire length of the roll, allowing users to see where to cut individual strips. The notches and perforations are spaced approximately 2.5 cm apart.