What Questions Should You Ask a Private Label Period Underwear Supplier?
A private label period underwear supplier should be questioned about far more than price and MOQ. Ask for the exact fiber percentages, gusset construction, absorbency test method, wash-cycle data, PFAS declarations, size tolerances, monthly capacity, inspection procedure, defect policy, and lead time. In the U.S., textile labels generally need fiber content, country of origin, and responsible-company identification, while California and New York restrictions on intentionally added PFAS in apparel took effect in 2025. A useful supplier should support each product claim with specifications, test reports, approved samples, and batch records rather than sales descriptions.
Start by asking how much of the product the supplier actually manufactures. Period underwear can involve body fabric, elastic, moisture-transfer material, absorbent layers, waterproof film, thread, labels, and packaging, so a factory may control sewing while buying laminated gusset materials from another company. Ask which processes are completed in-house, which are subcontracted, and whether the same subcontractors will be used after sample approval.
That manufacturing map should lead directly to material specifications. Ask for fiber composition by component, fabric weight in g/m², stretch direction, elastane percentage, membrane type, gusset thickness, and whether the absorbent layer is knitted, nonwoven, terry, or another structure. Under U.S. textile law, fibers representing 5% or more of total fiber weight generally have to be identified by generic name and percentage, subject to applicable exceptions.
A material specification is useful only when the bulk order follows it, so ask how substitution is controlled. Your purchase specification can state that no fabric, membrane, elastic, thread, dye, adhesive, or gusset component may be changed without written approval, including technically “equivalent” replacements.
Ask the supplier to identify every functional layer in the gusset separately. A statement such as “four-layer absorbent technology” does not tell you the fiber composition, basis weight, liquid distribution, waterproof material, or construction method.
Once the construction is clear, move to performance claims. If a supplier says one brief holds 20 mL, 30 mL, or “four tampons,” ask how that figure was measured, what liquid was used, how long the sample was allowed to absorb, whether pressure was applied, and whether the result represents maximum saturation or leakage-free capacity. Two laboratories can produce different numbers when the procedures differ.
The better follow-up is to request a written test protocol before comparing suppliers. At minimum, record sample size, conditioning, liquid volume, application rate, test position, leakage definition, and number of repetitions; using 5 samples per size or construction is more informative than approving a claim from one garment. Ask for raw results rather than only a pass/fail certificate.
Performance also changes after laundering, so a new sample should not be the only reference. ISO 6330:2021 defines domestic washing and drying procedures for textile testing and includes 16 Type-A washing procedures, 12 Type-B procedures, 7 Type-C procedures, and 6 drying procedures. Ask which wash condition the supplier uses and whether the report states it.
For reusable underwear, specify checkpoints such as new, 10, 25, and 50 wash cycles. Measure garment dimensions, elastic recovery, gusset shape, lamination condition, leakage, color change, and absorbency at the same checkpoints; a product that passes before washing but loses performance after 25 cycles should not be represented by the original result.
Wash data should then be connected to care instructions. The U.S. Federal Trade Commission requires manufacturers and importers covered by the Care Labeling Rule to provide cleaning instructions, so ask whether the proposed wash temperature, drying method, bleach restriction, and ironing instruction are based on tested construction rather than copied from another style.
Chemical compliance needs its own discussion because period underwear combines skin-contact textiles with water-resistant materials. New York prohibits the sale of new apparel containing intentionally added PFAS from January 1, 2025, and its guidance tells retailers to obtain compliance information from manufacturers or suppliers. Ask for a signed declaration that identifies the product, materials covered, date, and responsible company.
California requires another level of attention. AB 1817 restrictions took effect on January 1, 2025; regulated PFAS include intentionally added PFAS and, under the law’s threshold approach, total organic fluorine at or above 100 ppm beginning in 2025, tightening to 50 ppm in 2027. Ask whether testing covers the finished garment or only one fabric.
That distinction matters because a garment can contain several sourced materials. Request declarations or reports for the body fabric, gusset face, absorbent insert, waterproof membrane, elastic, print, and any finishing treatment, then record supplier names or lot references so later production can be matched with the approved bill of materials.
| Ask the supplier | Information you should receive |
|---|---|
| What is the body fabric? | Fiber %, g/m², knit structure, stretch and shrinkage data |
| What is inside the gusset? | Layer-by-layer material and construction |
| How is absorbency stated? | Test method, sample count, results and failure definition |
| What happens after washing? | Results at agreed wash-cycle checkpoints |
| Are PFAS intentionally added? | Signed material/product declaration and relevant test data |
| What changes require approval? | Written component-substitution procedure |
After materials and testing, move to fit. Request a full measurement chart with tolerances for waist, hip, leg opening, front rise, back rise, gusset width, gusset length, and elastic dimensions. A specification such as 72 cm ±1 cm is much easier to inspect than “medium fits true to size,” and tolerance should be defined for every graded size.
Do not approve only one sample size if the range is broad. For an XS–3XL program covering seven sizes, a practical development plan can include the base size plus at least 2 additional graded sizes before bulk approval, especially one near each end of the range. Ask whether gusset dimensions remain fixed or increase with garment size.
Fit approval naturally leads to MOQ because size and color breakdowns determine commercial feasibility. Ask whether MOQ applies per style, color, fabric, waistband, or complete order; “500 pieces MOQ” can become 500 pieces per color when custom dyeing is involved. Also ask whether the factory imposes a minimum quantity for each size.
Get the quotation in the same structure. Separate garment cost, custom fabric, printing, labels, packaging, testing, sample development, mold or setup fees, and inspection charges, then ask for price breaks at quantities such as 500, 1,000, 3,000, and 5,000 units. A lower unit price is not comparable when testing, packaging, or labels are excluded.
Price should then be checked against production capacity. Ask for normal monthly capacity for period underwear, current line loading, peak-season lead time, and capacity available for repeat orders. If an initial order is 1,000 pieces but the brand may need 10,000 within several months, ask how many sewing lines and trained operators could be assigned without changing approved materials or construction.
Capacity numbers should be paired with a dated production schedule. Ask for separate days for material sourcing, lab dips, sample approval, cutting, sewing, final inspection, packing, and shipment; a quoted “30-day lead time” is less useful than a schedule showing which approval starts those 30 days and what happens if a fabric arrives late.
Quality control belongs in the same production discussion. ISO 2859-1 was updated to its 2026 third edition for acceptance sampling by attributes, replacing the 1999 edition. Ask which sampling plan the factory or third-party inspector uses rather than accepting the phrase “AQL inspection” without the inspection level, lot size, sample size, and acceptance limits.
Your inspection checklist should separate functional defects from appearance issues. Gusset misplacement, damaged waterproof film, open seams, incorrect measurements, wrong labels, contamination, and missing components should not be treated the same as a minor loose thread; define defect categories and acceptable limits before production starts.
A pre-production sample should be treated as a manufacturing reference, not a showroom sample. Keep one approved unit with the brand and one sealed reference at the factory, both identified by style, color, size, approval date, and revision number.
The same control should apply to labels and packaging. FTC guidance states that most covered U.S. textile products must disclose fiber content, country of origin, and the manufacturer or another responsible business; a U.S. company may use an FTC Registered Identification Number instead of its name. Review artwork before thousands of labels are printed.
Packaging should be quoted separately because garment MOQ and printed-box MOQ may differ. Ask for unit dimensions, carton quantity, carton measurements, gross weight, barcode placement, size sticker location, insert requirements, and whether mixed-size cartons are allowed; these details affect warehouse receiving and freight calculations before the first shipment leaves the factory.
Finally, put defect handling into the purchase terms before paying the deposit. Define the claim period, documentation required, responsibility for rework, replacement timing, freight responsibility, and treatment of failed inspections. If a 3,000-piece order contains a repeated construction defect, the agreement should state how the affected quantity will be identified and resolved rather than leaving the remedy to an email discussion after delivery.