Materials & Fabrics · 4 min read · Buyer questions: Q0043, Q0046
How to Choose Fabric for Custom Running Shirts
Mesh or smooth knit? Start with the wearer, conditions and print requirements, not GSM alone. Compare swatches and define what the sample must prove before bulk production.
The decision in one paragraph
Choose a running-shirt fabric by linking its structure to the wearer, climate, artwork, fit and care expectations. GSM is one controlled measurement, not a performance grade. Compare the actual swatches, then confirm the important claims through a garment sample or an agreed test method.
Start with the runner and the conditions
A useful fabric brief begins with use, not a supplier fabric code. State whether the shirt is for a short road race, regular club training, long-duration trail use, volunteer staff or a retail range. Add expected weather, layering, fit, colour and the areas that carry graphics.
This context changes what should be compared. A loose participant shirt with a large sponsor print creates a different decision from a close-fitting club singlet worn in heat. The buyer should define the decision before requesting “lightweight performance fabric”.
- Wearer group and intended fit
- Climate, duration and layering
- Areas of high sweat, pack contact or abrasion
- Artwork coverage and required colour
- Care instructions and expected use cycle
Use GSM as one measurement, not the verdict
GSM describes fabric mass per unit area. ASTM D3776 provides methods for measuring that mass, including a small-swatch option whose result applies to the tested sample rather than automatically to the whole production lot. A quoted GSM therefore needs a measurement basis and an agreed tolerance if it matters commercially.
Two fabrics at the same stated GSM can still differ in yarn, knit geometry, density, finish, stretch, opacity, hand feel and airflow. A higher GSM does not by itself prove better durability, and a lower GSM does not by itself prove better cooling.
Compare mesh and smooth knit without relying on labels
Mesh and smooth knit are broad visual descriptions rather than complete specifications. Record a swatch reference, fibre composition, construction, colour, finish and approved end use instead of approving the word “mesh”.
| Decision | Mesh structure | Smooth knit structure | What the buyer should check |
|---|---|---|---|
| Surface | Openings may be visible and vary in scale | More continuous visual surface | Front and reverse swatches under the same light |
| Airflow | Open geometry may change air movement | Depends on yarn, density and finish | Ask for comparable test data if airflow is a requirement |
| Print detail | Openings can interrupt fine marks | May present a more continuous print surface | Print the smallest real logo and text at final size |
| Opacity | May show skin or base layers more readily | Can still become translucent when stretched | Check dry, stretched and wet appearance where relevant |
| Snag risk | Larger openings may expose loops | Surface may be less open but still snag | Review use, packs, hook-and-loop contact and an agreed test |
Translate performance words into evidence
Words such as breathable, moisture-wicking and quick-drying describe different questions. ASTM D737 measures air permeability. AATCC TM195 evaluates liquid moisture-management behaviour from the fabric structure and the fibres or yarns. Other AATCC methods address wicking and drying rate. One result should not be presented as proof of every comfort claim.
Decide which property matters enough to test. If formal testing is not justified for the project, compare named swatches using the same practical sample protocol and state the limitation clearly.
Move from swatch to garment sample
A swatch helps compare touch, structure, colour and print trials. It cannot show the finished garment’s fit, seam behaviour, panel interaction or appearance when stretched. The garment sample should use the intended fabric and artwork where those factors drive the decision.
Record what the sample is intended to approve: construction, fit, colour direction, artwork reproduction or a combination. Unchecked properties remain open rather than silently approved.
What to confirm for your project
- Named fabric reference and supplier version
- Composition, construction and stated GSM with tolerance
- Colour reference and approval method
- Actual artwork trial at final scale
- Required tests or practical comparison protocol
- Garment sample purpose and approval record
Questions to carry into supplier review
- Does a lighter fabric automatically dry faster?
- Should the same fabric be used for the body and ventilation panels?
- What changes when a dark print covers a large area of a light running shirt?
Standards and primary references
- ASTM D3776/D3776M — Mass Per Unit Area (Weight) of Fabric
- ASTM D737 — Air Permeability of Textile Fabrics
- AATCC TM195 — Liquid Moisture Management Properties of Textile Fabrics
- AATCC standard test methods and procedures
These references support the comparison method. They do not certify a KITRAVA product, facility or test result.