Whenever I have to spray fast-drying lacquer in the summer, I gird myself for blush. I’m sure you’ve encountered blush. It’s that whitish haze that looks like thin clouds trapped in the finish, and usually shows up when spraying during humid weather.
When things are going well, shellac and lacquer both dry very quickly because they cure strictly by having their solvent evaporate, and because very fast evaporating solvents are used in them. Normally, of course, that’s wonderful; I can spray quickly and have the piece dry quickly, a boon for those of us with less time than ambition.