Our 7 year old dark stained dining room table mostly used for mail and a laptop has an unforgiving finish that develops white rings under coffee mugs and pizza boxes. The white marks dissipate after a few days. The table was bought retail, not sure of the type of wood and current matte finish.

Does anyone have finish recommendation that could prevent the moisture marks? On a previous honey oak table we used gloss marine varnish, don’t think that is the right choice for this. I’ve used Lee Valley pure tung oil on stocks becuase it’s idiot proof. My understanding is tung oil won’t work without sanding off the existing finish. And I don't know if tung oil would prevent moisture marks.

I’ve never used modified tung oil, or Danish oil, maybe those are options over the existing finish? Increasing scratch resistance would be a plus.

Thanks