Explanatory notes
… (3) Fixers to make the developed image permanent (e.g., sodium thiosulphate (hypo), sodium metabisulphite, ammonium … aluminium or magnesium, in powder, tablets, foil, etc., and sometimes mixed with other substances to promote combustion. … Subheading 3707.90 covers light-sensitive plastic resin solutions ( “photoresists ”) used in the photolithographic …