1. Trace front and back, add 1 in (2.5 cm) seam allowance at side seams, inseams and centre back (for fitting), 3/8 in (1 cm) at the crotch curves, and 1 1/2 in (4 cm) at the hem. Leave the waist with 3/8 in.
2. Cut in calico or a cotton of similar weight to the final fabric, on the straight grain.
3. Draw on the cloth with a felt pen: hip, crotch and knee lines, and both crease lines.
4. Sew darts, side seams and inseams with a long stitch; then the crotch seam. Staystitch the waist and pin on a 1 in (2.5 cm) petersham or tape band. Use a short zip or pins at the CF or side.
5. Fit, standing, in the shoes to be worn. Check that the hip and knee lines are level and the creases hang straight down from front and back.
6. Then sit, squat, climb a step and walk. Mark pulls and folds with chalk; pin out extra cloth.
7. Photograph front, side and back.
8. Transfer every change to the paper block, one change at a time, and sew a second toile if the change was more than 1/2 in (1.3 cm).

Fit problems and their pattern fixes are in The crotch curve: shaping and testing and Fit changes on paper; the master list of symptoms is in Module 3.

• The CB slant: the seat sticks out behind the body; tilting the CB and lifting it 1 in gives more length over the seat, so the trouser does not pull down when sitting.
• The wider back (H/4 + 1 in): room for the seat and for sitting.
• The longer extension (H/10): the back extension wraps under the seat; it is always longer than the front.
• The 3/8 in drop at B13: it balances the inseam lengths and lets the back crotch sit closer under the body.
• The bigger dart: the back has more waist-to-hip shaping than the front, because of the seat.

• Two back darts: for a waist-to-hip difference over 12 in (30 cm), use two darts of 3/4 in (2 cm), 1 1/2 in (4 cm) apart.
• Full or flat seat: adjust after the toile, using Fit changes on paper.
• Back yoke: for jeans, move the dart into a yoke (see Darts, pleats and yokes on paper).
• Stretch woven: reduce hip ease to 1 in (2.5 cm), shared between front and back.
• Lined block: draft the lining from the block, with 1/4 in (6 mm) extra at the side seams.

1. Draw the back on the front framework in a second colour; it guarantees matching lines.
2. Measure the curves, not the straight lines, when checking crotch length: tape on its edge, following every curve.
3. Hold front and back together at the inseam against a window to check the joined crotch curve.
4. Walk the side seams together with a pin as a pivot; mark the notch at the hip line on both.
5. Use a felt pen grid on the toile; pull lines show at once against straight lines.
6. Use a long stitch on toiles so they unpick quickly for changes.
7. Professionals fit with wide seam allowances at the CB and inseam, so they can let out as well as take in.
8. Fit the back in a mirror and a photo; nobody can see their own back crotch.
9. Keep the first toile labelled with the date and the changes, even after the second.
10. Change one thing per toile where time allows; you will know what worked.
11. Sit on a hard chair for the sitting test; a sofa hides problems.

Back waist dips when sitting

Cause: not enough back rise or seat room.

1. Raise B10 by 1/2 in (1.3 cm) and redraw the waist.
2. Lengthen the back crotch extension by 1/4–1/2 in (6–13 mm).
3. Prevention: sit-test every toile on a hard chair.

Folds under the seat

Cause: too much back length or crotch depth for a flatter seat.

1. Pin out a horizontal fold below the seat and transfer it to the pattern.
2. Shorten the back extension by 1/4 in (6 mm).
3. Prevention: use the flat-seat change in Fit changes on paper.

Inseams will not match

Cause: back crotch point dropped too far, or inseam curve too deep.

1. Raise B13 by 1/8 in (3 mm) at a time.
2. Reduce the inseam hollow.
3. Prevention: check inseam lengths before cutting the toile.

Side seams swing forward or back

Cause: front and back widths not balanced for this body, or creases off the grain.

1. Move 1/4 in (6 mm) of width from front to back (or back to front) at the side seam.
2. Check the creases are on the straight grain.
3. Prevention: draw the side seam on the toile and check it is vertical.

Back dart pokes out

Cause: dart too short or too wide.

1. Lengthen the dart towards the fullest point of the seat.
2. Split it into two smaller darts.
3. Prevention: no single dart over 1 1/4 in (3 cm).

The waist gapes at the CB

Cause: swayback, or the CB slant too steep for this body.

1. Pin out a wedge at CB below the waist and transfer it.
2. Take the extra into the CB seam.
3. Prevention: check the side view at measuring.

Toile fits, final trouser does not

Cause: toile cloth very different from the final fabric.

1. Make the toile in a cloth of similar weight and stretch.
2. Re-fit in the final fabric, basted, before topstitching.
3. Prevention: choose the toile cloth to match the fabric.

• Skipping the toile because the maths looks right. Fabric does not follow paper exactly.
• Fitting only standing. Most trouser problems show when sitting.
• Myth: “The back is just the front made bigger.” Its shape, slant and extension all differ.
• Changing several things at once between toiles.

1. Easy: draft the back at quarter scale over your quarter-scale front.
2. Medium: run the six paper checks on your full-size block and write the results on it.
3. Medium: sew a toile and fit it with a partner; photograph and mark it.
4. Hard: make two toiles with one change between them; describe the difference in writing.

As a hobby: the toile is where your trouser becomes yours. Keep it; it is a record of your body.

For earning: some studios include a toile fitting in made-to-measure orders and build it into the time estimate (see Module 12 on costing as a method).

For teaching: pair learners to fit each other’s toiles with checklists. Teach them to describe what they see before suggesting a fix.

• After the last toile, true every seam on the paper and copy the block onto card.
• Store the final toile folded with the block, labelled.
• Write the tested date on the block; re-check it if the body changes.

• A standard, widely taught method, written for this book; D&D has no drafting method of its own. Schools vary the CB slant (3/4–1 1/4 in), the back extension (H/10 to H/8) and the drop at the crotch point (1/4–1/2 in).
• The crotch seam lengths quoted are measured on our draft and rounded; yours will vary a little with how the curves are drawn.
• All figures are for a D&D teacher to check on a toile.

1. Can you draft the CB slant and back rise?
2. Do you know why the back extension is longer than the front?
3. Can you run the six paper checks?
4. Do you sit, squat and walk in every toile?
5. Do you transfer toile changes to the paper one at a time?

• Back rise: the extra height at the CB waist above the waistline.
• CB slant: the angle of the centre-back seam, giving seat room.
• Toile (muslin): a test trouser in cheap cloth.
• Pull lines: creases that show where cloth is short.
• Easing: sewing a slightly longer edge to a shorter one without pleats.