There is definitely a lot of confusion around the subject of the difference between lacquer and varnish. Just click on all the results on the first page of google and every one of them seems to contradict the other. After some research, I have found that some of the things I believed to be true, simply are not. So in this post I am going to explain what I know to be true through my experience.
Varnish was much more popular in times gone by. It has a very tough but brittle finish. I mean brittle in the sense that you were taught in physics class. Varnish, while tougher than lacquer, tends to crack when dented. This means that air and water (or other liquids) can get in between the cracks and start to lift the varnish. Whereas Lacquer, though slightly softer (only slightly these days!), is much more durable. It doesn’t scratch quite as easily and, when dented, maintains its waterproof seal on the floor.
If you were to take a sheet of varnish (just imagine) and try to bend it, it would snap almost immediately. Lacquer would be pliable and bend.
And lastly varnish is much more susceptible to UV damage. This means that the sun coming through your window will damage and discolor your floor or furniture. Water-based lacquers these days are very UV-stable. Any damage actually happens to the wood underneath and not to the lacquer itself and it takes much longer to happen.
Lacquer ingredients and manufacture methods are changing ALL the time. They are getting stronger, more durable, more usable and better looking. Already they are far and away the best pick for your wooden floor. Just recently I heard about a new lacquer that is fortified with ceramic!!! Which gets me way more excited than it really should do. Hopefully soon I will be featuring an article about this new lacquer here at HowToSandAFloor.com