A corset is one of the most structurally complex garments a home sewist can make. It is not simply a tight bodice — it is a multi-layered engineered understructure designed to redistribute and support the body. This guide explains how corsets are constructed and what each layer does.
The Layers of a Corset
A properly constructed corset has at least three functional layers:
- Fashion fabric (outer layer) — the decorative exterior visible when worn
- Structural interlining — typically sturdy cotton canvas or coutil. This is the most important layer: it is where the boning channels are sewn and where the grommets are installed. It carries all the structural load.
- Lining (inner layer) — soft cotton or silk against the skin, hides the construction and protects the structural layer
Boning Channels
Boning channels are strips of fabric or twill tape sewn to the structural interlining to create pockets for the bones. Each channel must be sized to fit the bone snugly — too loose and the bone rattles and migrates; too tight and it is difficult to insert and may cause fabric distortion.
Heidi typically uses 1-inch twill tape for boning channels on the structural interlining, stitching from the right side of the interlining so the stitching is visible and controllable. She tests the width of each channel as she goes.
Grommets
Grommets are installed at the back opening for the lacing. Key steps:
- Mark grommet positions precisely with a basting stitch line as a guide
- Add an extra layer of canvas at the grommet area for reinforcement
- Punch from the right side (exterior) for a cleaner hole
- Press firmly and completely — a partial punch tears rather than cuts
Construction Sequence
- Assemble the structural interlining pieces and sew boning channels
- Insert bones and cap the ends (electrical tape on cut ends prevents poking)
- Add extra canvas reinforcement at the grommet area
- Install grommets
- Assemble fashion fabric pieces
- Join fashion fabric to structural interlining (wrong sides together)
- Attach lining, finish top and bottom edges
- Lace and do a fitting — adjustments are far easier at this stage
Heidi's Personal Note
My first several corsets did not fit correctly — I made them in progressively smaller sizes, going from a 16 all the way down to a size 8 before I got a correct fit. The lesson: always start with a mockup in cheap fabric (I use cable ties from the hardware store as mock boning and wrap the ends in electrical tape). The mockup stage is not optional when you are learning to fit corsets.