Rothys The Flat Black Honeycomb Round Toe Women's ballet Slip on Shoes Knit from Rothy’s signature thread (spun from plastic water bottles). Soft, flexible upper —which means no break-in period, ever. Comfortable insoles Fully machine washable, so it’s like new again and again. Our shoes don’t stretch much—so make sure they are not too snug. Most customers recommend going up half a size for narrow feet and a full size for wider feet in this style.