Umbra undies: What You Need

Binding methods may affect the seam allowance

If using fold over elastic (FOE) or doing knit binding, you may wish to trim away the seam allowance at the legs and waist before cutting. If you keep the seam allowance, the finished product will have a slightly higher waist and slightly smaller leg openings.

A serger/overlock is nice, but optional

As with all knitwear and stretch fabrics, a serger/overlock will make your life easier. If you do not have one of those, don’t despair. You don’t really need it. You can just sew Umbra with a zigzag stitch or with various other stretch stitches.