Ozotype and Allied Processes 
OzotTyPEe Process.—This process is based on the transfer 
of the hardening effect of a chromate salt formed by exposure 
to light in the presence of a colloid, to another film containing 
a pigment. 
A well-sized paper should be chosen, or be sized with a 
2 per cent solution of gelatine. With rough or absorbent 
papers it may be necessary to give two or three coats, allow- 
ing to dry after each. Or the following may be used: 
Soluble starch 100 g 768 gr. 
Water 200 ccm 4 oz. 
Rub into a cream, and add to: 
Boiling water 800 ccm 1Z\oz: 
Allow to boil for 5 minutes, then filter through thick linen, 
and add: 
Formaldehyde 50 ccm 25 min. 
Alum 0.5¢ 3.8 gr. 
An almost clear solution that keeps well should result. Pin 
the paper to a board, and with a pad or flat brush paint the 
surface until it appears uniformly wet. Papers with very 
smooth surfaces may be floated on the above, diluted with an 
equal volume of water, or a 10 per cent solution of fish glue 
may be used in the same way. The paper must be thoroughly 
dried. The sensitising solution may be (Manly) : 
Potassium bichromate 50 g 384 er. 
Manganese sulphate 50 g 384 gr. 
Water 1000 ccm 16 oz. 
Or (Hubl): 
Potassium bichromate 60 g 460 er. 
Manganese sulphate 30 g 230 gr. 
205 
