Blocking confuses knitters because every fibre behaves differently after washing. Here’s the clear answer: most natural fibres need re blocking, but TeaCosyFolk acrylic cosies don’t. With acrylic, a gentle wash, a flat dry and one warm teapot session will reset the cosy perfectly without pins. This guide explains why acrylic responds to heat, how to reshape a cosy after washing and the simple method that keeps TeaCosyFolk designs looking new.