A.Carl Hagstrom responds: When nail holes are filled prior to staining or clear coating, it’s difficult to get a good match. The filler will always absorb stain or finish at a different rate from the wood, and it typically ends up darker. Preparing a test board and filling holes with different blends of filler will help, but it’s a time-consuming process.

A much simpler (and practically foolproof) method is to use a product called Color Putty (Color Putty Co., 121 W. Seventh St., Monroe, WI 53566; 608/325-6033). This linseed-oil-based putty is about the consistency of Play-Doh, and it’s available in more than a dozen wood-tone colors. For best results, first apply any stain and all finish coats and allow them to dry, then fill the nail holes with the Color Putty. Use your thumb to push the putty into the holes, and wipe off any excess with a paper towel dampened with denatured alcohol. I wear a pair of latex gloves to prevent the color pigment from working into my skin.

The directions on the container recommend applying the final finish coat after filling the nail holes, but this can cause problems. If excess putty isn’t completely removed by the denatured alcohol, the residual putty haze will show through the finish coat.

By kneading two or more colors together, a wide range of color variations are possible, and with a little patience, you can achieve a perfect match. One caution: Never use denatured alcohol to wipe down an alcohol-based shellac finish. Most other finishes will not be harmed by denatured alcohol, but it’s always a good idea to test the finish in an inconspicuous area.

Carl Hagstrom is an associate editor of the Journal of Light Construction.