- Anti fit sweatpants for boys. Drawstring at the waist. Tapered fit. Enzyme washing gives a soft feel. The model is wearing a size 152 and is 158 cm tall . JACK & JONES JUNIOR Jersey fabric Jersey is the traditional kind of sweatwear. The one you know from classic sweatshirts; usually grey with a melange effect. This icon of knitted fabrics has been around for centuries; people around the world love jersey for its comfort and versatility.