隻舉一例：照相到銅板上，此時銅板成了底片。再塗上化學溶液，黑的部分腐蝕重，越黑越重。洗幹淨，銅板成了印刷底片。

來源: 空城之主於 2025-10-19 19:39:43 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

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