Perhaps you have just finished varnishing a beautiful French door. Maybe you were refinishing the frame of a beat-up old mirror. Whatever happened, you got varnish on the glass and now you want it off. Well, here are a few options for you.
There are a few things you can do to remove varnish from glass. First of all, make sure that you have wiped off all varnish that is still wet. You can remove the dry varnish with something like Goo Gone and a dry Mr. Clean Magic Eraser. Take care that you do not remove the lacquer from the area surrounding the glass unless you mean to do so.
Some people recommend using a sharp razor blade (like the kind you can get from the Stanley website) along with some soap or Windex to moisten it in order to get lacquer off of glass. If you do this, be sure to keep your razor blade at a low angle so you do not scratch the glass. Do not use it on smoked or frosted glass, though, as it has been known to cause scratching on this kind of surface. Also take care if you try to use the razor blade method on tempered glass, as it tends to be a bit more (excuse the pun) temperamental about being scraped, as the standards for making a good tempered glass are no longer as high as they once were, resulting in fabricating debris which you can inadvertently dislodge with a razor blade and which can result in scratches.
Other methods you can also use to remove varnish from glass are lacquer thinner, denatured alcohol, or rubbing alcohol, which can dissolve the lacquer (and that makes sense, since lacquer is basically resin dissolved in some kind of volatile solvent). Another, more environmentally-friendly (in case you are sick of being in stinky surroundings) suggestion for removing dried varnish from glass is to use baking soda as a mild abrasive on the surface and buff the blemish away. If you want to power that idea with a little "oomph," you can add some water and a few drops of ammonia, making sure to wash the solution off after rubbing it onto the surface with a good cloth.