I am about to apply a varnish/lacquer to a fairly non-small countertop (200x50cm). Because it'll be in the bathroom I want to apply it on all sides. I also want to minimize the amount of times I have to turn it around and want to minimize the amount of stains on the visible edges.
One solution seems to be to paint while keeping the countertop vertically, so that any stains from drips will form on the small side that'll be invisible in my case. But how do I hold the countertop while working and how do I rest it while it dries?
And if the better option is to apply it while it's laying flat, how can I avoid stains on the underside?
 - I don't really understand what's the difference, they both translate to the same word in Polish.