How to Start an Underwear Brand: OEM Manufacturing Guide for New Brands

Starting a custom underwear brand runs through four phases across six steps: define the range, write a tech pack, approve samples, then place a production order. The tech pack is the first deliverable, because a reliable supplier quotes from measurements and fabric weight rather than from a style photograph, and a brief that arrives as a photo comes back as a guess.

This guide is written from the supplier side of the table. Xiamen Unitex Trade Co., Ltd. is a sourcing and trading company that programmes underwear and sleepwear through partner factories in the Xiamen–Quanzhou–Jinjiang knitwear cluster in Fujian. We own no production facility; the partner factories hold an amfori BSCI audit position and work with OEKO-TEX Standard 100 certified fabrics. What follows is the sequence a first OEM order actually runs on, the numbers that decide it, and the paperwork that stops the second order from drifting away from the first.

What are the four phases, and how long does each step take?

The elapsed times below are the ones that hold for a first order in cotton or cotton/elastane knit. They are not a schedule for a licensed print programme, where artwork approval sits outside the factory and can take as long as the production itself.

Two things about that table are worth stating plainly. The first is that stage 2 costs you nothing at the factory and saves the most: a tech pack that names measurements and fabric weight removes the single largest source of re-quotation. The second is that the pre-production sample is the only sample with a contractual job. Development samples are conversation; the PPS is the document that an inspector works from, and a defect that is not visible against the PPS is not a defect.

What belongs in the tech pack, and why each line changes the price?

A tech pack is not a design document. It is the set of statements a costing clerk can price and an inspector can test against. Twelve lines carry almost all of the difference between two quotes for what looks like the same boxer brief.

Where a brand has no tech pack, the workable substitute is a reference garment plus a signed measurement chart. It is a perfectly normal starting point — most first-time buyers arrive with a garment they like and a spreadsheet of measurements taken off it — but the measurements have to be written down and agreed before a sample is cut, because a sample made to an unrecorded measurement cannot be corrected, only replaced.

Which standards belong in the brief?

Naming the standard is what turns a preference into a specification. None of the following is exotic; all of it is routinely written into underwear briefs, and leaving it out is what produces a shipment that meets the sample and fails the market.

• Shrinkage. ISO 6330 sets the domestic washing procedures and ISO 5077 sets how dimensional change is measured. The threshold is a commercial decision, but the method is not: a shrinkage figure quoted without the wash programme and the number of cycles behind it cannot be compared with anything.
• Colourfastness. ISO 105-C06 for washing, ISO 105-E04 for perspiration, ISO 105-X12 for rubbing. On underwear the perspiration test matters as much as the wash test, because the garment sits against skin under a waistband.
• Pilling and abrasion. ISO 12945-2 for pilling on knitwear; abrasion resistance for the seat and inner thigh, where a light single jersey fails first.
• Flammability, United States. 16 CFR 1610 applies to wearing apparel. Plain-surface fabrics at or above 2.6 oz/yd² (about 88 g/m²) are exempt from the test under 1610.1(d)(1); raised-surface fabrics such as brushed flannel are not exempt on weight, and fabrics made entirely of acrylic, modacrylic, nylon, olefin, polyester or wool are exempt by fibre under 1610.1(d)(2). The exemption removes the test, not the standard.
• Harmful substances. OEKO-TEX Standard 100 is the product certification buyers normally ask for; Class II is the one that covers articles worn next to the skin, and a certificate is valid for one year, so the expiry date is part of the question you ask.
• Azo colourants, EU. REACH Annex XVII entry 43 restricts certain azo dyes to 30 mg/kg for each listed amine in textile articles that may come into contact with skin.
• Fibre labelling. Regulation (EU) No 1007/2011 requires fibre composition as percentages using permitted fibre names; in the United States the Textile Fiber Products Identification Act and its rules at 16 CFR 303 do the same job, and 16 CFR 423 requires care instructions.
• Sampling. ISO 2859-1 is the acceptance sampling standard behind an AQL figure; an AQL without the inspection level is not a specification.

How many sample rounds should a first order expect?

Three, and the third is the one that matters. The first round proves construction: seam type, waistband recovery, print placement, whether the fabric has the hand the buyer imagined. The second round proves fit and grading, and this is where a brand with no pattern history spends its time, because a size set that is right at the middle and wrong at both ends is a grading problem rather than a sewing problem. The third round is the pre-production sample, made in bulk fabric and bulk trims, sealed and signed.

Two rules keep the rounds short. Send the measurement corrections as numbers per point rather than as comments on a photograph. And approve the fabric and the colour before the fit round, not after it, because a fit sample in the wrong fabric is a sample you will have to make twice.

What is the minimum order, and why is it per style and per colour?

The figure that matters is per style and per colour, because a colour change is a new dye lot. Two colours of one style are two dyeing batches, and in a bulk order that is exactly where shade variation between cartons comes from.

A first season is therefore usually built from a small number of styles rather than from a wide one. Three styles in two colours each is a coherent launch at 2,000 pieces per style per colour; nine styles in one colour each is the same volume spread across nine dye lots, nine patterns and nine inspection references, which is more work for the same money and more risk per style.

What is inspected, and against which acceptance number?

Final inspection runs to ISO 2859-1 at the AQL and inspection level written into the purchase order. The common setting for underwear is AQL 2.5 at inspection level II, with the acceptance and rejection numbers taken from the tables rather than agreed in conversation. The defects that actually get found on underwear are consistent: measurement outside tolerance at the waist and leg opening, skipped stitches at the crotch seam, shade variation between cartons, print off-register at the side seam, and a waistband that has lost recovery before packing.

Two structural points sit outside the acceptance number. A critical defect — a broken needle fragment, a detached small part on a child’s garment — is not accepted at any AQL, because it is a safety event rather than a quality rate. And a defect that is not visible against the sealed pre-production sample is not a defect, which is why the PPS has to be signed before bulk starts rather than admired.

The detailed sequence for what happens when goods do arrive wrong — the notice windows, the documents and the remedy — is set out in the claim and replacement timeline, and the arithmetic of reworking a lot versus taking a credit is worked through in rework or discount.

What must be in the purchase order before the first cut?

• The measurement chart with its tolerances, referenced as an annex rather than described.
• Fabric: blend, weight in g/m², structure and finish, plus the shrinkage threshold and the method used to test it.
• The AQL, the inspection level, and who holds the right to inspect and to reject.
• The sealed pre-production sample, identified by date and by signature.
• The packing configuration and the carton marks.
• The delivery window in weeks from PPS approval, not a calendar date that assumes everything else went right.
• The notice window for defects on arrival, and the remedy that follows it.
• The trade term, and where title and risk pass.

Most first orders that go wrong commercially do not go wrong in production. They go wrong here: no tolerance on the measurement chart, no shrinkage threshold, no inspection right, no notice window. Each of those is a paragraph, and each paragraph is cheaper before the goods exist than after.

Where do first orders usually fail?

Five causes account for most of it, and four of them are buyer-side documents rather than factory-side failures.

• Fabric specified by trade name only. “Cotton-modal” is not a specification; the blend ratio and the weight in g/m² are, and they are what the quotation is actually built on.
• Colour approved on a screen. A colour approved on a monitor is approved under a light source the garment will never be seen in. Approve a lab dip or a physical swatch, in daylight, and note the light source.
• No measured size set. One approved sample in one size is not a graded range, and the sizes at the ends of the range are where the returns come from.
• No sealed PPS. Without it, the inspection has no reference and every disagreement becomes an opinion.
• No claim window in the purchase order. The defect that appears after the second wash is the expensive one, and it is the one a missing clause turns into a favour rather than a claim.

What does a reliable supplier actually do differently?

The difference is not in the sample, because every supplier can make one good sample. It is in what happens between the sample and the shipment: whether the fabric lot is recorded, whether the colour is checked against the approved swatch at the start of each dyeing batch, whether the measurement chart is re-measured in-line rather than only at the end, and whether the person who quoted the order is the person answering questions about it in week six.

For a first-time brand that difference is worth more than a small difference in unit price, because the cost of a late or inconsistent first order is not the unit price — it is the season, the launch date and the retail slot. A short checklist for the questions that separate the two is in the twelve-point supplier verification checklist, and the sequence for using it before a first order is in verifying a supplier before the first order.

Next step

Send the reference garment or the sketch, the fabric you have in mind with a weight, the size range you sell, the destination market and the quantity per style and colour. We will return a costing built on those inputs, a measurement chart template to fill in, and the sample lead time for the fabric you have chosen. Start from the OEM product categories, or look at men’s underwear programmes and kids’ underwear programmes for the base styles that shorten a first development.

Development and production run through Unitex’s partner factories in the Xiamen–Quanzhou–Jinjiang knitwear cluster, Fujian Province, south-east China.

Last updated: 2026-11-05 · Xiamen Unitex Trade Co., Ltd. — OEM & ODM underwear sourcing partner

Unitex Underwear (Xiamen Unitex Trade Co., Ltd.) — OEM/ODM underwear sourcing and supply-chain partner in Xiamen, China; in the trade since 2009, incorporated in 2013. Based in the Xiamen–Quanzhou–Jinjiang knitwear cluster, Fujian Province, south-east China.