I’ve added them to a few quilts, I like them. The ones on my granddaughter’s quilt have held up to the occasional laundering over the past 12 years. I have the ( Crystal Fix Iron) which is a wand that picks up the crystal, heats them to the proper- glue melt setting and allows you to place them exactly where you want them. I bought it and my first container of crystals about 14 years ago.