Measurements you need
Tape horizontal around the narrowest part of your torso, usually ¾–1⅝ in above the navel. Snug but not tight; don't pull in your stomach.Tape horizontal around the narrowest part of your torso, usually 2–4 cm above the navel. Snug but not tight; don't pull in your stomach.
Usually 22⅞–43¼ in.Usually 58–110 cm.Tape horizontal around the fullest part of your buttocks, allowing for the curve of your stomach. Stand straight, feet together.Tape horizontal around the fullest part of your buttocks, allowing for the curve of your stomach. Stand straight, feet together.
Usually 33⅛–51⅛ in.Usually 84–130 cm.At the side, from the waistline down to the level where you measured the hip. It helps to tie a ribbon at the waist and measure from it.At the side, from the waistline down to the level where you measured the hip. It helps to tie a ribbon at the waist and measure from it.
Usually 7⅛–8⅝ in.Usually 18–22 cm.From the front waist, between the legs, to the back waist. Tape not pulled tight. Optional measurement: the pattern maker uses it to check the seat seam.From the front waist, between the legs, to the back waist. Tape not pulled tight. Optional measurement: the pattern maker uses it to check the seat seam.
Usually 23⅝–29½ in.Usually 60–75 cm.How the underwear is drafted
The top edge circumference — between your waist and hip measurements, depending on the rise — is multiplied by the fabric stretch factor and split between the front (48%) and the back (52%). The top of the front dips by 1 in2.5 cm toward the center, and the side widens toward the bottom, where the body is wider. The seat length — the crotch length at the top edge — is divided between the front, the gusset and the back. The leg opening is chosen so that it stretches to the length of the opening line on the body: if it falls short, the side gets lower and the opening deeper.
We checked the draft against proven commercial patterns for the same style: the key measurements match.
The pattern maker checks the draft itself: the top edge circumference, matching side seams, the gusset lining up with the front and back seams, the seat length and the leg opening. The results appear in the "Draft check" section.
How to sew
Place the two gusset pieces together, sandwich the front and back between them, and sew each side with a single seam — the raw edges end up inside. Sew the side seams. Attach elastic at the top and around the leg openings, fold it under and topstitch. Sew with a serger and a stretch stitch.
How to print and tape
Download the PDF on Letter or A4 sheets and print at 100% scale, without "fit to page". The first sheet has the test square: measure it with a ruler. Sheets are taped with an overlap along the ⅜ in1 cm strips; sheet numbers and the assembly guide are on the first page. For a copy shop or plotter, choose "One-sheet PDF".
What you get
The front and back on the fold and the gusset at full size, with seam allowances and hem allowance for the elastic. The whole pattern comes on several Letter or A4 sheets.
FAQ
Which rise should I choose?
Low (bikini) — the top sits 3½ in9 cm below the waist, with a short side. Mid — 2 in5 cm below the waist. High — almost to the waist, covering the tummy. The pattern maker calculates the top edge circumference for the rise you choose: between your waist and hip measurements.
What fabric should I use?
Cotton knit with Lycra (jersey, interlock), viscose with elastane, swimwear lycra. Cut the gusset twice: the outer one from the main fabric, the inner one from cotton jersey. Choose how much the fabric stretches: stretch 3⅞ in10 cm across — up to 5⅛ in13 cm is slight, 13–16 is medium, more is high stretch.
How much elastic do I need?
The pattern maker shows it below the drawing: about 0.88 of the body circumference at the top edge for the waist, and about 0.9 of the opening for each leg. Sew lingerie elastic with a zigzag, stretching it slightly, then fold it to the wrong side and topstitch again. The seam allowance at the top and leg openings equals the elastic width.
Why is the crotch length measurement needed?
It sets the seat length of the underwear — from the top edge at the front, between the legs, to the top edge at the back. Without it, the pattern maker estimates it from your hip measurement. If underwear usually cuts in or, on the other hand, hangs loose at the crotch, take the measurement: from the waist at the front, between the legs, to the waist at the back.