Instructions (English) on how to make this Romper Pattern. Sizes: 0-3 months, 3-6 months, 6-9 months, 9-12 months, 12-18 months, and 18-24 months. Experience level: Advanced Beginner. Yarn and needles: DK weight yarn, 2,5 mm - US2, and 3,5 mm - US4 needles. Worked Flat. This is a digital file, not the actual finished item. You cannot resell this pattern but you can sell the finished item! ©Berta Knit Store All Rights Reserved. Baby Knitting Patterns. PDF Knitting Patterns. Etsy.