Cashmere, a luxury fiber known for its softness, is delicate and expensive. When your cashmere sweater gets wrinkled, you can't just toss it in the washer and dryer, as this will damage it beyond repair. While dry cleaning will get the wrinkles out, the chemicals are unnecessarily harsh. If your sweater has been folded on a closet shelf all summer, steam-blocking it is the best method of removing the wrinkles before you wear it again.
Flatten a large cardboard box and lay your cashmere sweater on it. Fill a steam iron with water and allow it to heat up.
Smooth the sweater with your hands. Pin all the way around the edge of the sweater with straight pins, sticking them into the cardboard. Stick the pins in just far enough to anchor the sweater and keep it flat, using one pin every 2 to 3 inches. Be careful not to stretch the sweater as you pin.
Hold the iron approximately 1/2 inch above the sweater. Press the steam button to release a short burst of steam.
Move the iron over the entire surface of the sweater, never allowing it to touch the fabric. Release short bursts of steam as you go. The sweater should be damp, but not wet.
Allow the sweater to dry completely before unpinning it. This can take up to a day, depending on the temperature and humidity level in the room.