The moisture-excluding effectiveness (MEE) of 91 finishes was evaluated on ponderosa pine sapwood. The Forest Products Laboratory method was used in which finished and unfinished wood specimens conditioned to 30% relative humidity at 80°F were weighed before and after exposure to 90% relative humidity at 80°F for various time periods. Finishes with the best MEE were pigmented and non-aqueous. Two-component epoxy paint systems had MEE values greater than 85% after 14 days when three coats were applied. MEE was a direct function of the film thickness and the length of exposure to a particular humidity. Only 11 finishes retarded moisture vapor movement into wood over 14 days, and then only after application of two or three coats. The effects on MEE of repeated adsorption/desorption cycles are described. -- AATA