Supplier Size Inconsistency: Holding Factories to Spec

To stop supplier size inconsistency, give the factory a measured spec sheet, agree tolerances in writing, approve a sample before production and inspect finished garments against the spec. Without those steps, "size M" can mean different things in each batch.

Inconsistent garments also break size advice. An AI size recommendation for fashion stores is only as good as the size chart behind it, and the chart is only true if the garments match it.

Why do factories produce inconsistent sizes?

Most inconsistency comes from unclear instructions and uneven checking, not bad intent. Common causes include:

• A spec that lists labels but not measurements.
• Different cutters or lines working to different patterns.
• Fabric that shrinks or stretches differently between rolls.
• Patterns graded by a different method between runs.
• No final check against the spec.

What goes into a spec sheet?

A spec sheet lists each measurement point for each size, with a tolerance. It is the document both sides can point to in a dispute.

Include these elements:

• Measurement points, such as chest, waist, hip, length, sleeve and inseam, with a short description of where to measure.
• Target values for every size you sell.
• Tolerances, which are the allowed differences from the target.
• Fabric and wash notes, so measurements are taken at the right stage.
• Reference sample, a garment both sides agree is correct.

Agree tolerances for each point with your supplier. Tighter tolerances cost more attention, so ask for them where fit is most sensitive.

How do you approve a sample before production?

1. Send the spec sheet and a reference garment if you have one.
2. Receive a pre-production sample in your fit size.
3. Measure it yourself and record every point against the spec.
4. Request a size set, which is the same style in the smallest and largest sizes, to check the grade.
5. Approve in writing, or send corrections and ask for a new sample.

Check more than one size. A grade error often shows up only at the ends of the range.

How do you inspect finished garments?

Inspect before the goods ship, while the factory can still fix problems. You can use your own team, the supplier's quality team or a third-party inspector.

A simple method:

1. Pick a random set of cartons and garments from the finished batch.
2. Measure each selected garment at every spec point.
3. Compare with the target and tolerance.
4. Record results by size, so you can see patterns.
5. Decide whether to accept the batch, request rework or reject it.

Ask the supplier which sampling plan they use, and agree on it before production. Whichever you choose, write it into the purchase order.

What should you do when a batch is off?

Compare the measurements, not opinions. If garments fall outside the agreed tolerance, you have a documented reason to ask for rework or a credit.

If the batch is only slightly off, you may decide to sell it and update the size chart to match the real garments. Publishing an accurate chart is better than a wrong one.

How do you write supplier expectations into your contract?

Put the rules in the purchase order, not only in emails. A clear order should state:

• The spec sheet version that applies.
• The tolerances for each measurement point.
• The sample approval step before production starts.
• The inspection method and who pays for it.
• What happens if goods fall outside tolerance: rework, discount or rejection.

Keep a copy of every approved sample and spec version. If a dispute comes up, you can show exactly what was agreed.

Start with one or two key styles if the supplier is new to you. Building the habit on a small order costs less than fixing a large one.

How do you keep the size chart honest?

Build your published chart from measured finished garments, not from the supplier's label. Update it when a new batch differs.

On the product page, show the measurements shoppers can compare. The product page checklist for fashion stores covers fit notes and photos.

In ZeDaq.ai, you enter your own size chart in the dashboard, one per garment type, and the body scan recommends your labels from it. That only works if the chart reflects the real garment.

How do sales data reveal supplier problems?

Returns for size reasons that cluster around one batch or style are a clue. Track returns by style and by delivery date.

Use that data when you forecast demand by size, because noisy garments make sales by size unreliable. Also make sure each size is easy to identify in storage, as described in labeling sizes clearly in your stockroom.

FAQs

What is a tolerance in garment measurement?

It is the allowed difference between the target measurement and the actual garment. You agree it with your supplier for each point.

Should I trust the size label from my factory?

Use it as a starting point, then measure finished garments yourself.

How many garments should I inspect?

It depends on your batch size and your agreed sampling plan. Ask your supplier or inspector which plan applies.

Can I fix inconsistent sizes with a better size chart?

A chart that matches the garments helps shoppers choose well. It does not fix the garments, so keep working with the supplier too.