Case Study: How a Stockholm Yoga Label Stopped Its Sizing Drift by Moving Production to the Factory

The order at a glance

The problem: nobody could say who made the bestsellers

The brand's complaint had three parts: it could not trace which factory actually made its best-selling styles, the sizing moved from one batch to the next, and every technical question took a week to come back.

Those three symptoms usually share one cause. When an order passes through a middleman, the brand owns a product but not a specification. Each production run can land on whichever factory or line is free, and each one works to its own reading of the last sample, its own measuring habits and its own knitting program. Nothing in that chain is wrong on its own, but nothing anchors one run's medium to the next run's medium either. Questions take a week because they travel through two inboxes and, often, a translation step before anyone who can see the machine answers them.

Swapping suppliers fixes none of that unless the brand ends up owning a specification the new factory works to. That is what the three steps below set up. For the wider picture, see our guide to telling an activewear factory from a trading company.

Step 1: Rebuild the two hero styles from a reference garment

We worked from a reference garment: a finished piece of each hero style.

Rebuilding a seamless style from a reference garment means measuring it flat and relaxed at defined points, reading the knit structure and zoning, and turning that into a knitting program and finishing specification the factory controls. The output is not a copy of the old garment's mistakes; it is a written baseline that every future batch is measured against. The program then went through two fit rounds: sample, try on, correct, and sample again, until the fit was signed off.

Step 2: Lock the grade rules to the brand's published size chart

A brand's size chart is a promise to its customers: whoever orders a medium expects the measurements printed on the website. Grade rules are the steps between sizes, how much the waist, hip, rise and inseam change from one size to the next.

Locking the grade rules to the published chart means every size in every lot is checked against that chart, not against the previous batch. Measuring each batch against the last one is how drift happens: small differences add up run after run until the medium no longer matches the chart. With the chart as the fixed reference, a lot that moves outside tolerance is caught before it ships. Our guide to activewear sizing and grading explains how grade rules are set.

Step 3: In-line and final AQL checks on every lot, with photo reports

Every lot went through two kinds of inspection. In-line checks happen while the lot is still being made, when a measurement or knitting problem can still be corrected on the machine. Final AQL inspection is a statistical sample of finished, packed goods before shipment, which decides whether the lot ships as it is.

With photo reports, the brand sees the measurements and pictures of each lot from the people who checked it, instead of a summary passed along by a middleman. Our guide to activewear quality control and AQL inspection covers how sampling levels and defect limits work.

The outcome

Two things changed, as recorded on the project: batch-to-batch sizing stabilised, and technical questions now go straight to the production floor, with no relay through a middleman. The order was a full custom seamless program: 500 pieces per style across the two styles, shipped by sea freight.

What other brands can take from it

• Ask who makes each style. If your supplier cannot name the factory behind your bestseller, you cannot hold that factory to a specification.
• Own your baseline. Keep a reference garment, its measurements and its grade rules on file, so any factory can be measured against the same thing.
• Measure against your published chart, not the last batch. Your customers read the chart, so that is the standard every lot should meet.
• Ask for photo reports on every lot. Measurements and photos from the people doing the inspection are faster to act on than reassurance passed along.
• Time your technical questions. If a simple answer takes a week, count how many hands the question goes through.

FAQ

How can I tell if my activewear is made by a trading company?

Ask your supplier to name the factory that makes each style and to send production photos from that line. A factory can show its own machines, people and process; a trading company usually relays answers and may move orders between factories. Our guide to telling a factory from a trading company lists the checks we would run.

Why does activewear sizing change between batches?

Usually because nothing fixes the measurements. When each batch is made against the previous one, by different factories or lines, small differences add up. Locking the grade rules to the brand's published size chart, and measuring every lot against it, keeps a medium the same from run to run.

What does it mean to lock grade rules to a size chart?

It means the steps between sizes are written down and tied to the size chart your customers see. Every size in every lot is measured against that chart, so a lot that drifts outside tolerance is caught before it ships instead of becoming the new baseline.

What is the difference between in-line and final AQL inspection?

In-line checks happen during production, while problems can still be corrected on the machine. Final AQL inspection samples finished, packed goods before shipment and decides whether the lot ships. This brand had both on every lot, with photo reports.

What does moving a style from a trading company to a factory involve?

In this case: a reference garment for each hero style, two fit rounds, grade rules tied to the brand's size chart, and in-line plus final checks on every lot. The order ran at 500 pieces per style; full custom development usually requires 300–500 garments per style per colour.