English edit

Noun edit

alpha paper (uncountable)

  1. (UK, dated, photography) A sensitized photographic paper for obtaining positives by artificial light. It is coated with gelatin containing silver bromide and chloride.
    • 1939, Herald, volume 5:
      The sheets of alpha paper which have been grained are first dipped in soft acetate remaining there for three minutes. They are dried in an oven and made ready for impregnation with hard acetate.