Development. The development of the print and subsequent operations are as in ordinary carbon process. (See Carbon Printing.)
Gtim-Ozotyfte. It is only necessary to point out the variations which are involved when pigmented gum is used instead of a pigmented gelatine tissue, and we may refer readers to an article on gum-ozotype contributed by Mr. W. R. Bliss to The Amateur Photographer for July 26th, 1901, p. 63.
A little gum (or fish glue) is desirable in the sensitising solution Mr. Bliss recommending the following mixture: -
Ozotype sensitising solution, ...... drms.
Water ............... ,,
Mucilage of gum ............20 minims.
Coating, printing, and washing are as in the ordinary ozotype process.
The washed and dry sheet bearing the brown image is now coated with pigmented gum to which an equivalent of the trans-ferring solution has been added. We have found the following mode of working to be satisfactory.
Grind suitable moist colour or " tube colour" (see Gum-Bichromate) with twice its bulk of mucilage of gum, prepared as directed in the article on gum-bichromate. Then to each fluid ounce of the mixture add 4 minims of acetic acid and 2 grains of hydroquinone, working all together in the mortar. Next paint the dry and washed sheet bearing the brown image with this mixture ; proceeding as directed in the article gum-bichromate, but with the difference that the coating may be so thick as just to obscure or hide the image on the paper. Hang the sheet up to dry, and in twelve or eighteen hours develop as directed for gurri-bichromate.
Packing Plates. Several methods are employed by commer-cial firms to preserve dry plates from accidental injury and fracture whilst travelling, and a convenient method for the tourist is that practised by a well-known London firm. Pure tissue paper is cut the exact width of the plates, but sufficiently long to enclose five or six; the end of a strip is placed in the box, then a plate is laid in face downwards, and the tissue paper folded over the back of it; then another plate is laid face down-wards on the tissue paper, and this is continued till the case is