| 摘要 |
PURPOSE:To provide a fine printing matter without the generation of ground soiling by burning in a lithographic plate under the presence of borofluoric acid salt. CONSTITUTION:In a burning method for a material for lithographic plate after it is subjected to image exposure and development, the lithographic plate is made by burning in the material under the presence of a borofluoric acid salt or by treating the material with a solution containing borofluoride after burning-in. When using this treatment for the counter-etching pretreatment, for example, even if a plate held as it is after burning-in is used for printing, a fine printing matter is obtained without any ground soiling. Even though said pretreatment is incompletely performed so as to leave a portion not having coated with said salt, the counter-etching effect still extends to this portion from the circumference to prevent the ground soiling. Further, execution of the counter- ethcing aftertreatment can remedy the ground soiling generated from lack of the counter-etching treatment. |
