1)indelible ink,Silver nitrate ink 2)Electoral finger staining,can't be easily washed off 3)violet to black,used for election ... 1)Indelible ink,Silver nitrate ink2)Electoral finger staining,can't be easily washed off3)violet to black color,used for ... )also called silver nitrate ink,since it can't be washed by water ,it mostly yo be used for voting and election,the content ...