Film & darkroom
Developer storage: keep the bottle and the record together
Separate concentrate, stock, working solution and reuse history.
An opening date by itself does not describe a chemical bath. A stock solution made from powder, a newly diluted working solution and a used bath have different histories. Make that history visible on the container and in the session log.
Use product-specific storage limits
ILFORD’s powder-developer sheet gives storage guidance for its named products and distinguishes stock from diluted solutions. It also discusses the effects of reuse and oxidation. These instructions do not establish the storage life of another maker’s chemistry or of an unidentified bottle.
Evidence: Technical data sheet
A bottle label with useful fields
Our label has five fields: product, solution type, dilution, preparation date and reuse count. Put the associated technical-sheet reference in your notebook. Before a session, reconcile the bottle with the recorded history; if they disagree, do not guess which entry is right.
Measure the work you actually do
After each session, update the roll count and note the film formats processed. Record a visible anomaly and retain a representative result for comparison. A reuse limit is not a promise that every stored bath remains effective until that number: preparation, contamination and storage conditions remain part of the process.
Sources & further reading
Sources for the specific facts and product descriptions above. Our worked examples, interpretations and practical suggestions are original editorial guidance.
- ILFORD PHOTO — PERCEPTOL, ID-11 and MICROPHEN technical dataTechnical data sheet