how can use black watermark ink

a lot of customer want to know how to use of black watermark ink by screen or offset.for exsample,we choose screen printing to talk about that:

1.first time you need ready your design logo.
2.after make mesh as like 200~250mesh,some one call 80~100T.
3.remember shake evenly,when you get watermark ink.after used,keep it for cooland ventilated place.

remind: balck watermark ink surface was white,after printed still can see white color on surface.if you want to white invisible,used offset printing was better.or dark paper.