Which finish is this

[Pirate]

The person we bought the house from installed some wainscoting and I'm trying to decide what finish he put on. He is no longer around to ask.
It looks like a colorless finish.
What tests with solvents, etc can I do? Any other ideas?

[JR1]

Unfortunately the only finish hat you can definitively identify is shellac. Put a few drops of alcohol¹ some where inconspicuous, if after 15 minutes the finish softens then it is shellac. The other tests for lacquer and waterborne finishes are o longer valid. Today lacquer thinner is mostly acetone and that will damage many finishes including varnish (but not conversion) and some waterborne finishes. There are several waterborne which are not affected by acetone (see the Thread in this form for John's recent tests). Waterborne used to be polyurethane or acrylic but now can be pretty much anything including: polyester, epoxy, conversion varnish etc.

¹ No need to go buy DNA to test for shellac, any alcohol will work—vodka, rum, tequila… just so long as it's at least 100 proof.

[Howard Acheson]

"Google" What finish is this?

[JR1]

I did and my remarks above still stand. Xylene will not reliably dissolve waterbased/waterborne finishes, lacquer thinner (acetone) will dissolve many varnishes as well and not touch some waterborne finishes.