These are straw sandals, a lightweight and quick-drying type, made by wrapping nylon cores with a new "mame shibori" (bean-print) tenugui (hand towel) and braiding them. They are softer than yukata fabric, so they may tear easily, but they feel good against the skin. The black polka dots sometimes have red marks, which are from the printing process. It is not blood. They are recommended for those who wear approximately 24-24.5cm (US size 7-8) shoes. To wash, hand wash and put them in a net for spin-drying, or if using a washing machine, put them in a net and use the delicate cycle. Please wash them separately as the color may fade. If the thong loosens or feels tight after wearing them for a while, untie and retie the thong on the underside. These are handmade items, so they are not perfect. Please understand this before purchasing. Please refrain from purchasing if you have a dog allergy.