Abstract: Disclosed is a correction fluid prepared by adding a stannous chelate compound having an acid phosphate ester of an aliphatic alcohol as a ligand to an aqueous acidic solution. The correction liquid forms a hydrophilic stannous chelate compound precipitate, when the pH value of the liquid is elevated. Accordingly, where the correction liquid is coated on the unnecessary line image part of an electrostatic master paper plate and the pH value of the thus coated liquid is elevated, the unnecessary line image part of the plate is to be coated with the hydrophilic and water-insoluble stannous chelate compound so that it becomes insensitive to ink. The operation for such correction may be effected at any stage before or after the lipophobication treatment of the electrostatic master paper plate to be corrected with the correction fluid.

Abstract: A lipophobicating solution for an electrophotographic plate for offset printing is disclosed which comprises (a) phytic acid, (b) a diamine having the general formula NH.sub.2 --R--NH.sub.2 wherein R is an alkyl or aryl group having from 2 to 8 carbon atoms, and (c) water. The pH of the solution is in the range from about 3.0 to about 6.0. This lipophobicating solution does not cause scumming and allows an electrophotographic process to produce clean printed sheets.

Abstract: A silver master plate recovery solution for a silver salt photographic plate for offset printing is disclosed which comprises (a) a hydrazine component for reducing the silver oxide layer of an image area, (b) a quaternary ammonium salt cationic activator and (c) water. The mixing ratio of the quaternary ammonium salt cationic activator is 3.0 to 20.0 wt % on the basis of the hydrazine component. The silver master plate recovery solution reduces the silver oxide layer of the image area of a silver salt photographic plate which has passed the stock time, thereby recovering the ink receptivity of the image area.

Abstract: A lipophobicating solution for an electrophotographic plate for offset printing is disclosed which comprises (a) phytic acid, (b) a diamine having the general formula NH.sub.2 --R--NH.sub.2 wherein R is an alkyl or aryl group having from 2 to 8 carbon atoms, and (c) water. The pH of the solution is in the range from about 3.0 to about 6.0. This lipophobicating solution does not cause scumming and allows an electrophotographic process to produce clean printed sheets.

Abstract: There is provided a lipophobicating solution for electrophotographic plates for offset printing which comprises (a) phytic acid, (b) two or more dicarboxylic acids selected from those represented by the formula HOOC--(CH.sub.2).sub.n --COOH (where n is 1 to 6) and phthalic acid, (c) water, and (d) a pH adjustor. This lipophobicating solution does not cause scumming and its effect lasts for a long period of time.