Treating historic finishes requires being able to discern the buildup of historic finish, repairs and polishes over the years onto the surface of an object. In many instances, these materials can be separated from one another to improve the appearance but maintain a historic coating in place.

This New England maple work table c. 1815 retains nearly all of its original painted school girl style decoration and varnish coating. Unfortunately, while the finish was old, it was also very dark and obscured. Testing indicated that the surfaces only needed careful cleaning with a water-based cleaning solution specifically formulated to remove years of dirt, oil, and other polishes, but leave the degraded varnish intact. The improvement in color and legibility was dramatic.