Q: How do I stretch out and soften a sweater vest that has “tightened up?” It hasn’t shrunk too badly.
A: From your description, it sounds like the garment is a woolen. If the sweater has hardened, the yarns have felted.
If you look at a wool fiber under a microscope, it will resemble a telescope with scales. When the wool fiber contracts, it’s as if the telescope closes; then the scales begin to tangle. This causes the shrinking and hardening of the yarn. This is usually the result of a combination of exposure to water, excessive heat and excessive mechanical action.
If the sweater was drycleaned, you may have excessive moisture in the solvent. This may be the result of a mechanical problem (such as a leaking steam coil, solvent cooler or condensing coil, or a clogged separator) or excessive use of moisture or water-based prespotting agents.
Severe cases of felting can’t be corrected. For minor felting, use a carding brush to detangle the yarns. Then, use bottom (buck) steam while stretching the fabric. Use the vacuum when the garment reaches the proper size. It may be necessary to repeat the procedure to achieve the proper size if the fabric has shrunken severely.