Simplicity Sewing Pattern S9129 Learn to Sew Adults Child Sleepwear Trousers. This pattern is suitable for sizes A (XS-L/XS-XL). Learn-to-Sew: Child’s, teens’ and adults’ lounge trousers. Note: if used as sleepwear, use fabrics and trims that meet UK flammability standards. This is an amazing pattern, perfect for dressmaking. Brand: Simplicity, Size: A (XS - L / XS - XL), Craft: Dressmaking, Style: Trousers, Pyjamas, Difficulty: Easy.