Lessons · Lesson 3 of 6
A body is not a garment: ease is a decision
Tell a body chart from a garment chart by looking at the numbers, and treat ease as a written policy across the range rather than a fact about one fit.
Lesson 3 of 6 · 18 min
26 August: two tables under one heading
Ostley's PLM holds the women's bottoms sizing in one place, and inside that one place there are two grids. One is the body chart from lesson 1. The other is the finished-garment specification the tech pack draws from. Neither carries a label saying which is which, because everybody who built the file knew.
On 26 August the new scan chart is exported into the tech pack template for OS-2214. It lands in the columns Yatawara reads as the garment specification. Chamila catches it in about four minutes, and how she catches it is worth more than the incident.
She subtracts.
A garment waist minus a body waist is the ease. This sheet says the size-10 waist is 75.9 and the body chart says the size-10 waist is 75.9. That is zero ease, and there is no trouser on earth with zero waist ease.
That is the whole test. You can tell which kind of chart you are holding by looking at the numbers, with no label at all, because a garment measurement is always a body measurement plus something. A size-10 women's trouser with a waist of 75.9 cm is a body. One with a waist of 77.9 cm is a garment. If you cannot decide which you have, you do not know what the number means — and neither will anybody downstream.
The document nobody writes
A complete sizing position has three documents. Most companies hold two of them.
- The body chart — what the person measures. Lesson 1 is about where it comes from.
- The garment specification — what a tape reads on the finished garment. Course 4.4 owns how that measurement is defined: the point, the method, the state and the tolerance. Read it before you argue about a reading.
- The ease policy — the bridge. Body plus ease equals garment, measurement by measurement, size by size.
The third one is almost never a document. It is worked out by subtracting the other two, which is exactly backwards, because the ease policy is the only one of the three that contains a decision. The body chart is a measurement. The garment specification is arithmetic. The ease is somebody's opinion about how this garment is meant to sit on a person, and it is the buyer's opinion to hold — not the pattern room's, and not the fit model's feeling on a Tuesday afternoon.
Course 4.3 takes the ease apart into wearing ease and design ease, and shows what happens when a fit comment is carried out word for word. Read it for that. What this lesson adds is what happens to an ease policy across a range, which is where digital tools make the problem bigger rather than smaller.
Ostley's ease policy for OS-2214
| Point of measure | Ease | Why it is that number |
|---|---|---|
| Waist | 2.0 | The band must close over a body that changes through the day |
| Hip | 6.0 | The seat reads clean and the trouser does not cup |
| Thigh | 4.0 | A straight leg, not a slim leg — this is the look |
| Knee | 8.0 | Design only; nothing physical requires it |
The fabric is a cotton twill with 2% elastane, and it stretches 18.0% across the width. That matters here for one reason, and people get the reason wrong: stretch does not remove the ease decision, it widens the range of legal answers. With this cloth, Ostley could have specified a hip ease of 6.0 cm as it did, or of zero, or of minus 3.0 cm for a body-skimming style. All three can be made. Whether the ease is positive or negative is a design decision. It is not a fit fact and it is not a property of the cloth.
The trap: a constant ease is not a constant fit
Ostley's policy holds 6.0 cm of hip ease at every size. That is the normal way an ease policy is written and it looks entirely reasonable. Set it against the bodies the scan actually found.
| Size | Measured hip | Ease | Ease as a share of the hip |
|---|---|---|---|
| 2 | 80.0 | 6.0 | 7.50% |
| 6 | 89.5 | 6.0 | 6.70% |
| 10 | 99.6 | 6.0 | 6.02% |
| 14 | 111.1 | 6.0 | 5.40% |
| 18 | 123.0 | 6.0 | 4.88% |
The same garment, made exactly to policy, carries 7.50% of relative room at the bottom of the range and 4.88% at the top. That is a fall of 2.62 percentage points, which is 35.0% less relative room at size 18 than at size 2. Nobody changed anything. The policy is constant and the fit is not, because the body underneath the policy is not constant.
Which is right? That is a decision, and it has two defensible answers. Holding the ease absolute — the same centimetres at every size — means the garment reads closer and closer as the range goes up. Holding it relative — the same share at every size — means the garment reads the same and uses more cloth in the large sizes. Ostley's designers, asked directly for the first time, chose relative at the hip and thigh and absolute at the waist, because a waistband is a closure and a seat is a silhouette.
Then the interesting part: price it.
| Line | Value |
|---|---|
| Extra hip girth at size 18 | 1.41 cm |
| Extra fabric at size 18 | USD 0.04 a garment |
| Fabric saved at size 2 | USD 21.42 across the order |
| Fabric added at size 18 | USD 59.68 across the order |
| Net across all sizes | USD 66.02 |
USD 66.02 on a USD 297,600 order. The small sizes give back most of what the large sizes take, because the buy is roughly symmetrical, and the net cost of the whole decision rounds to nothing.
That is the finding of this lesson. The ease policy across a range costs essentially nothing to change and is worth a six-figure difference in returns. At most brands it is not a decision at all. It is whatever fell out of the base size and got copied sideways.
Check yourselfA tech pack's sizing tab gives a size-12 chest of 96.0 cm for a woven shirt. Body or garment, and how do you know without asking?Show the answer
A body, almost certainly, and you know it by subtracting rather than by reading the heading. A woven shirt cannot be worn with zero ease at the chest, so a finished chest for a size-12 woman's shirt has to be a good deal larger than the body it fits — commonly by ten to twenty centimetres once design ease is in. A figure of 96.0 sits in the range of a body. The test works generally: take the number, ask what garment it would have to be for that to make sense as a finished measurement, and see whether anybody would wear that garment. Then send one line to the buyer confirming which it is, because being right and undocumented is worth nothing in November. And note what the test cannot do: it tells you the KIND of chart, never whether the chart is true.
What to take to your own range
- Label every sizing table with what it measures — body or garment — in the file name and in a field, not in a folder convention.
- Run the subtraction test on any table that arrives from outside. It costs a minute and it catches a whole class of silent disaster.
- Write the ease policy down as its own document, point of measure by point of measure, and get the buyer to own it. If it does not exist, you are guessing on their behalf.
- Decide plainly whether each ease is held absolute or relative across the range, and record the answer. It is nearly free in cloth, and it is the difference between a range that fits at both ends and one that fits at one.