Two treatment approaches offer the ability to reduce disfiguring cross-grain warpage in wood. Both approaches are designed to counteract warpage by minimizing the measurable difference in the widths (cross-grain dimension) of the concave and the convex surfaces of a warped panel. The approaches differ significantly, however, and each is employed only upon consideration of the specific circumstances of the warpage (the term warpage here will refer to the most common form of the defect found in historic artifacts the troughlike cupping of a board or panel). One technique, Induced Compression Set, shrinks a convex surface to the narrower width of the opposing concave surface, using moisture and physical constraint. The other technique, Glycol-Stabilized Expansion, swells a concave surface to the wider dimension of the opposing convex surface, using moisture followed by a bulking agent-low molecular weight polyethylene glycol- to maintain the swollen state indefinitely.