You can use detergent if you want to wash the leggings at the same time. Detergent won’t interfere with the shrinking process.
Shrinking will make the leggings both tighter and smaller, so remember that the length and width will both change. Polyester is a synthetic material that requires higher heat to shrink and therefore might need several runs through the entire process. Polyester requires temperatures of 155 - 178°F to shrink. [5] X Research source It can take 5-10 cycles to shrink an item sufficiently so don’t give up after the first try. [6] X Research source If needed, lower the heat setting to make sure that the garment dries completely but doesn’t shrink. [7] X Expert Source Rani GorgisLaundry & Cleaning Specialist Expert Interview. 12 April 2021.
If you don’t have a washing machine, boil a large pot of water, add the leggings and boil for about ten minutes. Then, carefully remove the leggings and press out the water. Alternatively, you can soak your leggings in warm water overnight. [8] X Research source
Be sure to stand the iron on its end while preheating. Never leave an iron laying face down on the ironing board as this can start a fire.
You can skip the dish-drying towel if your leggings are 100% cotton.
Make sure you keep moving the iron so your leggings don’t burn and so the friction works to shrink the leggings. Don’t use the steam setting on the iron, as this defeats the purpose. Don’t forget to unplug the iron and leave it standing on its end until it has fully cooled. If you don’t have an iron, you can follow this method using a hairdryer. You won’t need a dish-drying towel but still spread the leggings on an ironing board. The process will take a little longer but the heat from the hairdryer can still work.
