This ultra-soft romper is made with PARADOU yarn (41% acrylic - 37% cotton - 11% linen - 10% viscose - 1% polyester). It is knitted in seed stitch on 3.5 mm needles. Youll need a 3.5 mm crochet hook to make the belt loops. This pattern is machine washable at 30°C maximum using the special wool program. Lay flat to dry and do not iron.