Vertex Sport Denmark: Trail Running Tanks Built on Core-Spun Cotton-Feel Polyester
Vertex Sport is a growing Denmark-based activewear label whose trail running tanks range now anchors its seasonal offer. When the design team planned a wider range with tighter launch dates, it needed a fabric partner able to guarantee construction consistency, documented performance and shade continuity across every production lot.
Vertex Sport: reviewing the fabric swatch set for the trail running tanks programme
The challenge
The main risk in the project was fit complaints caused by inconsistent GSM deliveries. The previous supply chain ran through a trading intermediary, so there was little visibility of the mill, no construction sheet and no test evidence behind the performance claims. Without that documentation the brand could not brief its retail partners with confidence.
The solution
We proposed a dedicated core-spun cotton-feel polyester programme built around a locked GSM and width tolerance documented per lot. Development started with A4 lab dips and a full construction sheet covering fibre content, GSM, width, stretch and recovery, and colour fastness. Only after the brand approved hand feel and performance targets did the project move to a pre-production lot for fit sampling.
Sample and fit approval for the core-spun cotton-feel polyester construction
Implementation
- Development: lab dips and physical samples in 5 working days.
- Approval: colour, hand feel and stretch signed off in two rounds.
- Bulk: consolidated dye lots to hold shade continuity.
- QC: inline inspection plus final random inspection before packing.
- Testing: ISO 13934 tensile strength on every bulk lot.
Specification delivered
| Parameter | Value |
|---|---|
| Fabric | core-spun cotton-feel polyester |
| Weight | 220 GSM |
| Width | 160–170 cm |
| Stretch | 4-way, recovery above 92% |
| Certification | OEKO-TEX Standard 100 |
| Colour fastness | Grade 4 or above |
Results
The new core-spun cotton-feel polyester programme helped Vertex Sport cut customer returns by 32% in the following season. The trail running tanks line launched on schedule, and wash durability, opacity and fit consistency all held up through the first retail season. The brand has since extended the programme into additional colours and styles.
“The development process was transparent from the first sample. We finally had the data we needed to brief our retail partners with confidence.” — Vertex Sport Product Team
Inline inspection and packing before the trail running tanks shipment
Key takeaway
Moving from a trading model to mill-direct development removed the hidden risks in the supply chain. With documented construction, controlled shade management and inline quality control, Vertex Sport could concentrate on design and marketing instead of firefighting production issues.
