The Thelma Boilersuit Size 20-28 Pattern by Merchant & Mills


A traditional workwear boilersuit with a gentler feminine fit. Thelma is a wardrobe masterpiece, loose enough to fit all shapes and can be interpreted in many different types of cloths, so make it your own.

Thelma will take time to put together, but make it well and wear it absolutely everywhere.

Skill level – experienced.

This is a multi-size paper pattern including sizes 20 – 28. You can find size 6-18 here.

Fabric requirements and further details below images.

3 in stock


All seam allowances are 1.5cm unless stated otherwise and are included in the pattern.

We would suggest using the following fabrics – medium weight wovens such as sanded twill, 5 – 8oz denims, yard dyed linens with some stability, and cotton poplin. If you are an experienced sewer you could try tencel, tencel/linen, corduroy, more floppy linens, prints and checks.

You will need:
16 x 14-18mm Buttons
2 x Matching thread
70cm Interfacing

Fabric Requirements (with or without nap)

Lining Requirements (in cm)

Finished Measurements (in cm)

UK Sizing