1) election ink for voting mark,bottle packing ,can't be washed by water
2) Blue color is good effect
3) sliver nitrate contending ,
indelible ink is also called silver nitrate ink,since it can't be washed by water ,it mostly to be used for voting and election,the content of the silver nitrate could be5%,10%,15%,25%.......it can be according to your require,and the more content of silver nitrate contain,the better effect it will be .
 

Indelible ink is used for election voting.  The silver nitrate indelible ink contents silver nitrate from 5 to 25%, and the colour in the finger can keep above 168 hours. 

    The ink can not be washed off by water, alcohol and bleach.we can offer  different colours , such as purple ,blue,green ,red and so on.

    The ink in bottle(from 30ml to 100mL) with a sponge,   aluminum sheet sealed,  inside plastic bage, and outside have the lable. We can produce at least 25000 bottles per day by the automatic filling machine.

    And the pen can keep 3mL ink. We can produce 50000 pens per day.