What is crosslinker?
Crosslinker is an optional additive that can be used with the Renner Waterbased Topcoat.
What is it for?
It makes the paint more chemically resistant. Therefore you may consider adding crosslinker to your topcoat if you were spraying a kitchen for example as it is a high traffic area.
If you do decide to add a crosslinker to your topcoat please check that you're mask provides you with the adequate amount of protection.