How to make a Dreadnought base?

What size cork do you use on your basing?

I have been following the steps you showed in this video and i applied the satin varnish then the pigments in water. Do you fix the pigments with Isopanol after and is this the reason for the satin varnish to protect paintwork underneath from alchol?
I love your videos especially the imperial fists recently.
i look forward to hearing from you.