How do you unshrink a woolen underlay?

To unshrink a woolen underlay, soak it in lukewarm water mixed with a gentle conditioner or baby shampoo for about 30 minutes. Gently stretch the fabric while it’s submerged, being careful not to pull too hard. Rinse it in cool water, then lay it flat on a towel to dry, reshaping it to its original size as it dries. This process can help relax the fibers, but results may vary depending on the severity of the shrinkage.