YXLP · Range plan
Seamless and Performance Underwear Range for Active Brands
An active range that pairs two constructions: seamless knit garments shaped in the knitting machine, and cut-and-sew performance garments in synthetic microfibre with flat seams. Seamless is intended to leave fewer visible seam lines, while cut-and-sew gives more control over leg length, seam placement and fit. Anti-chafe, moisture and odour behaviour are claims to prove with wear tests and laboratory evidence. The items below are starting specifications for development.
Development starting points, not stocked products. Availability, minimums and cost are confirmed in the quotation. Updated October 4, 2026.
Who this range suits
- Sport and fitness brands that need an underwear line to sit beside their apparel.
- Online sellers targeting runners, gym users and travellers.
- Brands that want a low-seam-line option as well as a cut-and-sew option built for movement.
Seamless boxer brief
A boxer brief knitted as a tube on a circular seamless machine, with zones of different stretch and structure.
Based on the seamless specification page.
| Fabric direction | Nylon or polyester with elastane, knitted as a tube. Composition is confirmed on the finished garment. |
|---|---|
| Weight starting point | Specified by yarn and machine gauge rather than by a single weight. Match a reference garment for hand and opacity. |
| Waistband | A knitted-in waistband, often with a jacquard or rib structure, and an optional logo knitted into the band. |
| Cut and construction | Zoned knit for the pouch, leg and back panel. Check how the crotch and leg openings are joined or finished on your reference. |
| Sizes | Often graded in fewer, wider sizes because the knit stretches, for example two or three size groups. Agree the groups and check the smallest and largest of each. |
| Colour and print | Colour comes from yarn-dyed yarn or from dyeing after knitting. Multi-colour yarn-dyed designs need their own yarn set-up, and garment dyeing needs a shade and fastness approval. Keep the colour set small for a first order. |
| Branding | A knitted-in waistband logo, a heat-transfer label or a printed tagless label. |
| Pack format | Single polybag with a hangtag or insert card. |
| Agree before bulk | Stretch and recovery after repeated washing, bonding or joined-seam strength, and fit across each size group. |
Performance long-leg boxer brief
A cut-and-sew boxer brief in synthetic microfibre with flat seams and a longer leg intended to reduce chafing, to be checked in a wear test.
Based on the performance specification page.
| Fabric direction | Polyester or nylon microfibre jersey with elastane. Composition starting point: roughly 8–20% elastane, a typical trade range, to be confirmed on the finished fabric. |
|---|---|
| Weight starting point | Specify weight and hand together by reference garment; very light fabrics can show seams and print through. |
| Waistband | A flat, soft waistband with a printed or woven logo, chosen so it does not roll during movement. |
| Cut and construction | Long leg with flat or bonded seams placed away from the inner thigh. A contoured pouch built to your reference. |
| Sizes | S to XXL as a starting grade set, with the leg opening and thigh graded separately from the waist. |
| Colour and print | Solid dark colours first. Dyeing synthetics to bright colours needs a colourfastness check, especially to perspiration. |
| Branding | Heat-transfer or silicone logo on the waistband or leg. Test the print on stretch. |
| Pack format | Single polybag with a hangtag. |
| Agree before bulk | Leg rise-up and chafing in a wear test, colourfastness to washing and perspiration, and seam strength. |
Lightweight microfibre travel trunk
A light trunk in synthetic microfibre aimed at travellers, with a short leg and a low-bulk waistband.
Based on the trunks specification page.
| Fabric direction | Nylon or polyester microfibre with elastane. Quick-drying behaviour is a claim to test on the finished fabric, not an assumption. |
|---|---|
| Weight starting point | A light fabric. Match a reference garment and check that it is not see-through in light colours. |
| Waistband | A low-bulk waistband that stays flat under clothing. |
| Cut and construction | Short leg with flat seams. A single-layer pouch is one option to test for drying time. |
| Sizes | Same grade set as the performance item. |
| Colour and print | Solid colours; keep the colour set small for a first order. |
| Branding | A small heat-transfer logo and a printed tagless label. |
| Pack format | Single polybag or a two-pack sleeve, with a compact fold for travel packs. |
| Agree before bulk | Drying-time test method and acceptance criterion if you will state drying behaviour, plus colourfastness and shrinkage. |
Every line is a starting point to adjust in your brief. Weights and compositions are common ranges to match against your own reference garment, and sizes follow the chart you supply.
Developing this range
- Decide which construction each item uses and what each should solve for the customer.
- Send reference garments or flat measurements so seam placement and stretch can be judged on a first sample.
- Name the performance claims you want to make and agree the test method and acceptance criterion for each.
- Wear-test the first samples for chafing, rise-up and comfort, not just measurements.
- Lock the size groups and fit-test the smallest and largest in each group.
What to send for a quotation
- Which of the three items you want, and for which sport or use.
- The claims you want to make, such as moisture management or drying time.
- Reference garments for seam placement and stretch.
- Colour set and any logo placement.
- Size groups and your size chart.
- Destination market and labelling rules.
- Target quantity by item and colour.
Common buying questions
How do I word a performance claim such as quick-dry or moisture management?
State only what a test supports: the method, the fabric or garment tested and the acceptance criterion, agreed before artwork is final. Antimicrobial and odour-control claims can also fall under separate regulation in some markets, so take advice before using them.
How do the seamless and cut-and-sew items share one size chart?
They usually do not share one grade. The seamless item is graded in a few wider groups, while the cut-and-sew items follow a conventional chart. Show both in your size chart and fit-test the smallest and largest garment of each group.
Which item should I start with?
Many brands begin with one item from each construction, then add colours or sizes once fit and claims are proven. Choose the construction that matches the problem your customer needs solved.
Are the seamless and performance items ready-made?
No. They are starting specifications for development, not stocked products. Availability, minimums and cost are confirmed in the quotation for the selection in your brief.