Can you leave your base board and quarter round unfinished?

you can leave them unfinished, but they will absorb water in a humid enviroment, and posibly stain. if you like the naturel look, wipe the trim down with a rubbing alcohol, let dry. use a clear varnish//polyurathan and apply with an old lint less cloth. poly comes in diffetent sheens...i used matt. if you can put the finish on before installing.

I agree with Dfm! It will easily get dirty and will be hard to keep clean. A finish protects the wood.

I agree with the comments above. Don't leave them unfinished. They will definitely get dirty and impossible to clean/

I agree with the comments above also. It will definitely end up dirty and not easy to clean.