Yes. We use chemicals to bind the dye to the fibers and to stop the dyeing reaction. Then we wash the fabrics with a special detergent that removes loose dye. The brightest and darkest colors (such as Phoenix and Mystic) are rinsed many times to try and get out all the unbound dye. That being said if you are someone who always washes your project when you are finished stitching - remember the threads are not colorfast and there could be loose dye in the fabric. It's recommended to rinse your piece in cold water and not let it soak.