While you can wash items that have iron-on patches properly attached, care must be taken. Only wash in cold to lukewarm water and where possible, hand wash the item. If washing in the machine, only use the gentle cycle. Always turn the garment with the iron-on patch inside out when washing it. Try to keep washing to a minimum, to preserve the patch and if its edges fray a lot, you may need to trim them or even stitch them back down.