A wholesale undershirt order needs two connected specifications: the garment the customer will wear and the assortment the retailer will sell. Agree on both before treating a per-piece quotation as a finished buying plan.
Start with the intended use, compare fabric samples under realistic conditions, then translate the proposed retail packs into garment quantities by color and size. Keep the units clear: 240 three-piece packs require 720 garments, not 240.
This guide shows how to make those decisions and assemble a practical enquiry for a private-label undershirt program.
This is the purchasing side of an undershirt programme. For the garment itself (neckline, body length, grading and washed size sets), see men’s undershirt development.
Define the layer before choosing the fabric
Describe what the undershirt will sit under and how it should fit. A close-fitting layer beneath a business shirt has a different brief from a relaxed undershirt worn around the home.
Record the intended customer, outer garment, neckline, sleeve coverage and tuck-in requirement. Include the target retail price and the care routine customers are expected to use. These details help the supplier propose relevant samples rather than a broad selection of fabrics with similar names.
Review initial samples on the intended body shapes. Look for bunching under the outer garment, visible neckline edges, restricted movement and a hem that pulls out when the wearer reaches or sits. A size label alone cannot establish whether the layering fit is correct.
For a starting point, review the undershirt development options and select the garment direction before requesting a quotation.
Treat GSM as one part of the specification
GSM means grams per square meter: fabric mass per unit area. It is useful for identifying and comparing a fabric, but it is not a complete measure of warmth, opacity, comfort or durability.
Two fabrics at the same GSM can use different yarns, structures and finishes. Two garments in the same fabric can also fit differently because of their patterns and construction. Choose a target weight after reviewing the sample, then document the agreed tolerance and measurement conditions with the supplier.
A useful fabric approval record includes:
| Specification | What to record |
|---|---|
| Fabric identity | Supplier reference and approved sample reference |
| Fiber content | Full composition, rather than a marketing name alone |
| Construction | Jersey, rib or other agreed structure |
| Finished weight | Target GSM, tolerance and measurement conditions |
| Color and finish | Approved reference and relevant finishing details |
| Stretch and recovery | Agreed method and acceptance criteria |
| Laundering behavior | Care procedure, number of cycles and measurement results |
Do not assign a universal summer or winter GSM to every market. Compare the finished garment for the intended climate, layering combination and customer preference.
GSM, opacity and fibre: what weight does and does not decide
- GSM and opacity: a heavier fabric is often more opaque, but yarn, knit density and colour change opacity at the same weight. Check show-through under a white shirt in each colour; see undershirt GSM and opacity.
- Fibre: cotton, modal, viscose and polyester blends feel and wash differently at the same weight; see cotton, modal and viscose undershirts.
- Measurement: fabric weight should be measured by a stated method, such as ASTM D3776, with an agreed tolerance; see GSM tolerance.
- Shrinkage: agree post-wash length and width limits; see undershirt shrinkage.
Compare candidate fabrics on the same brief
Cotton jersey, cotton-elastane and regenerated-cellulosic blends can all be candidates for an undershirt collection. Ask for a defined fabric reference and composition for each option. A broad label such as “modal blend” does not identify the knit construction, weight or finishing.
Compare samples using the same garment brief. Review touch and drape, coverage when stretched, ease of movement and recovery after wear. Repeat the relevant checks after the agreed care procedure. If one candidate requires a different pattern or construction, record that change rather than assuming the same fit will transfer.
Keep performance claims separate from fabric selection. If the retail brief includes moisture management or another functional claim, define what must be demonstrated and agree on supporting evidence. Do not infer the finished garment’s performance from the fiber name.
Decide color mix with the outer garment in view
Assess each proposed color beneath representative outer shirts. Compare neckline and sleeve visibility as well as the body area. Use consistent lighting and photograph the same combinations so the development team can compare them.
A color that is discreet under one shirt or on one wearer may be visible in another combination. Avoid promising that white, black or a particular skin-tone shade is universally invisible.
Choose the launch mix from the intended use and available demand evidence. If that evidence is limited, keep the opening assortment manageable and state that the ratios are provisional. Then ask the supplier to check the garment and material minimums for each color.
Convert retail packs into a production matrix
The following is a hypothetical planning example, not a recommended size ratio or an available Knitwear Base production program.
Assume one style is sold in same-size three-piece packs. The buyer plans 240 retail packs across three color combinations.
| Retail pack | S packs | M packs | L packs | XL packs | Total packs |
|---|---|---|---|---|---|
| Three white garments | 24 | 48 | 36 | 12 | 120 |
| Three black garments | 16 | 32 | 24 | 8 | 80 |
| Two white and one black | 8 | 16 | 12 | 4 | 40 |
| Total | 48 | 96 | 72 | 24 | 240 |
The resulting garment requirement is:
- White: 120 × 3, plus 40 × 2, giving 440 garments.
- Black: 80 × 3, plus 40 × 1, giving 280 garments.
- Total: 720 garments, consisting of 144 S, 288 M, 216 L and 72 XL.
Check this garment breakdown against the supplier’s quotation. A minimum of 300 pieces per color, if that were the agreed requirement, would leave black short by 20 pieces even though the overall order contains 720 garments.
Resolve the gap before purchase approval. Changing the pack mix changes both the retail assortment and the production quantities. Add any agreed spare units separately, and confirm whether they are to be packed for retail or supplied loose. Do not hide extra garments inside the retail pack count.
For the general minimum-quantity framework, see clothing MOQ explained.
Compare costs per sellable pack
Ask the supplier to state whether the quotation is per garment, per retail pack or per carton. Confirm what is included before converting between those units.
For a three-piece pack, the garment component is three times the quoted garment price. Add pack-level components only where they are not already included. Allocate freight, import charges and other relevant costs consistently across the order; confirm destination-specific charges with the appropriate logistics or customs adviser.
Compare the resulting cost with the retail plan. A cheaper garment can still produce a less attractive pack if it requires more expensive packaging, creates unwanted color inventory or leaves surplus material to be paid for.
Keep the manufacturing quantity and the expected sellable quantity separate when allowing for agreed samples, inspection use or other non-retail units.
Approve the sample and its evidence
Use the production-relevant fabric, trims and construction for final approval. If a development sample contains substitutes, identify them and state what still needs approval.
For the undershirt, record body length, chest width, neckline dimensions and other relevant points using an agreed measurement method. Repeat measurements after the defined care procedure and review appearance, seams and shape, including neckline recovery and any change in body length. Set the acceptance criteria before testing rather than inventing a pass limit after seeing the results.
For the retail pack, approve the number of garments, same-size rule, color combination and presentation. Keep the detailed packing instructions in a separate pack specification so this purchasing document remains easy to use.
For products sold in the United States, the FTC textile labeling guide explains the general requirements for fiber content, country of origin and responsible-business identification. The FTC care-labeling guidance also requires a reasonable basis for care instructions. Review the rules for the actual destination market before approving label artwork.
Packing, folding and carton checks for multipacks are covered in undershirt multipack packaging. The regulations themselves are in 16 CFR Part 303 (fibre content and origin) and 16 CFR Part 423 (care labelling).
Frequently asked questions
Is heavier fabric always better for wholesale undershirts?
No. The choice depends on the intended layer, fit, coverage and care performance. Compare finished samples against the product brief instead of using weight as a quality ranking.
Can one approved size cover the entire order?
It can establish a development reference, but it does not confirm the fit of every other size. Agree on the size-set review and record the grading and measurement requirements before bulk production.
Should MOQ be checked in packs or garments?
Check the unit used in the quotation. Retail packs must be converted into garments by style, color and size to evaluate garment minimums. Packaging may have its own separate minimum.
Prepare your undershirt enquiry
Send the proposed garment reference, fabric direction, target weight, color choices and pack matrix through Knitwear Base’s enquiry page. Include the destination market, care expectations and requested delivery date.
Ask the team to confirm feasible materials, project-specific minimums, sample requirements and quotation scope. The undershirt manufacturing page provides the starting service context; the confirmed specification and assortment should govern the actual order.
Sources and further reading
- ASTM D3776/D3776M, Standard Test Methods for Mass Per Unit Area (Weight) of Fabric
- eCFR, 16 CFR Part 303, Rules under the Textile Fiber Products Identification Act
- eCFR, 16 CFR Part 423, Care Labeling of Textile Wearing Apparel
- AATCC TM135, Dimensional Changes of Fabrics after Home Laundering
- ISO 6330:2021, Domestic washing and drying procedures for textile testing
- ISO 5077:2007, Determination of dimensional change in washing and drying
Rules and standards are summarised from their official pages for general guidance; this is not legal advice. Check the current version and the requirements of your own market before you rely on them.
