Use fabric weight to compare similar company shirts, not to rank every garment from worst to best. GSM means grams per square meter of fabric; it does not tell you what a finished shirt weighs, how well it fits, or whether employees will find it comfortable. A useful purchasing decision combines the weight with the exact fabric construction, intended wearing conditions and a decorated sample.
The practical question is not “What is the highest GSM our budget allows?” It is “Which fabric weight supports the experience we want, and what else must we verify before approving it?” That distinction matters when a supplier suggests a heavier substitute, a manager equates a substantial shirt with a better gift, or two quotes use different units.
Brand Sauce publishes this guide from a company-store provider’s perspective. The comparison process below is our recommended buying framework, not a claim that a particular weight, brand or fulfillment model always wins.
First separate three different meanings of weight
AS Colour’s fabric-weight explanation identifies GSM and ounces per square yard as measurements of fabric mass relative to area. Think of comparing equal-sized pieces of cloth, rather than putting two complete shirts on a scale.
| Specification | What it describes | Buying implication |
|---|---|---|
| GSM or g/m² | Mass of one square meter of fabric | Useful for comparing fabric specifications within a similar garment family. |
| oz/yd² | Mass of one square yard of fabric, expressed in ounces | Convert to the same units before comparing quotes. |
| Finished garment or packed weight | Mass of the actual shirt, or the shirt plus packaging | Useful for handling and shipping; not interchangeable with fabric weight. |
A larger size uses more material than a smaller size. Ribbing, pockets, seams and decoration also contribute to a finished garment’s mass. Weighing a medium shirt and an extra-large shirt therefore cannot establish which one uses heavier fabric. Likewise, a shipping listing that says “8 oz” may be describing something different from an apparel specification that says “8 oz/yd².” Ask which measurement the number represents.
For unit conversion, multiply oz/yd² by approximately 33.906 to obtain GSM, or divide GSM by 33.906 to obtain oz/yd². These are arithmetic conversions, not product test results. For example, 180 GSM is about 5.31 oz/yd²; 220 GSM is about 6.49 oz/yd². Rounded catalog values such as 5.3 and 6.5 can describe those same nominal weights.
Why “heavyweight” needs a garment category
Weight labels are useful shorthand within a range, but they are not enough to compare different kinds of apparel. In AS Colour’s published tee guide, the Staple 5001 is listed at 180 GSM, the Classic 5026 at 220 GSM and the Heavy 5080 at 280 GSM. Those examples also have different fits: regular, relaxed and boxy oversized, respectively. Moving up the weight range changes more than one variable.
Meanwhile, the manufacturer’s hoodie guide describes a 290 GSM Supply Hood as lightweight and a 350 GSM Stencil Hood as heavyweight. That does not contradict the tee descriptions. The comparison group has changed. These are examples from the manufacturer’s guides, not a promise of current stock, local availability or Brand Sauce assortment inclusion. Confirm the exact regional SKU and color before quoting.
Write “a substantial cotton jersey tee” or “a lighter layering sweatshirt” in the purchasing brief before selecting a numeric weight. Otherwise, a team can accidentally use a T-shirt preference to specify a hoodie, or approve an oversized silhouette when it only intended to request a denser-feeling fabric.
Choose a wearing job before choosing a number
The following table is a sampling plan, not a universal GSM standard. It deliberately describes what to compare and what would rule a candidate out.
| Wearing job | Useful comparison | Reason to reject a sample |
|---|---|---|
| Everyday tee under another layer | Two similar fits with different fabric weights | Uncomfortable bulk at the sleeve or neckline when layered. |
| Standalone team shirt | The intended light and dark colors in the actual fit | Unacceptable show-through or drape in normal wearing conditions. |
| Substantial, relaxed gift tee | Two heavier-feeling options with clear size charts | The preferred fabric comes only in a silhouette recipients do not want. |
| Apparel for an active workday | Samples worn during representative nonhazardous tasks | Wearers reject the comfort or movement, regardless of the weight specification. |
| Employee-choice assortment | Clearly differentiated lighter and more substantial options | Product descriptions hide the difference or imply one choice is inferior. |
Do not treat a fabric-weight number as evidence of thermal protection, visibility performance or other workplace safety suitability. Those decisions require the relevant product evidence and workplace requirements. For ordinary company gifts, the immediate objective is simpler: make sure the garment serves its intended use.
Keep the first comparison narrow. If one sample is a close-fitting polyester performance shirt and the other is a boxy cotton jersey tee, the result will not isolate a weight preference. Both might be worthwhile store options, but the buyer should describe them as different garment choices, not as a controlled light-versus-heavy comparison.
Use separate approval gates for quality and feel
A fabric-weight specification answers a mass-per-area question. It is not a test report for shrinkage, pilling, opacity, air permeability or decoration durability. Instead of making those properties stand in for each other, record a separate decision for each outcome that matters to the program.
- Fit and movement: evaluate the actual cut in relevant sizes, not just a folded sample.
- Appearance: review the selected colors under ordinary lighting and in the intended wearing arrangement.
- Decoration: approve the artwork at the proposed dimensions and placement on the actual garment.
- Care outcome: follow the label instructions and assess the result against agreed expectations.
- Specification confidence: retain the supplier’s style, composition, weight and revision information.
AS Colour notes that weight can affect drape and decoration behavior in its fabric-weight guide. That is a reason to sample the combination, not permission to approve all embroidery above a single GSM threshold. Artwork coverage, the garment and the decoration process still need to work together. Our decorated-apparel sample approval guide covers the broader release process.
For a wash-related requirement, define it directly. “Retains our agreed fit after the specified care trial” is more useful than “must be heavyweight.” The preshrunk shirt approval guide explains why a product descriptor should not replace that check.
A worked decision: two shirts, one brief
Illustrative scenario, not measured client results: a company wants a navy tee for indoor onboarding days and optional everyday wear. Candidate A is quoted as 5.3 oz/yd²; Candidate B is listed at 220 GSM. Both suppliers initially describe their product as suitable for company merchandise.
First normalize the units: 5.3 × 33.906 is approximately 180 GSM. Candidate B therefore has about 22% more fabric mass per equal area than Candidate A, using these rounded nominal values. That calculation does not mean the complete shirt weighs 22% more, lasts 22% longer or is worth 22% more money.
Next compare the rest of the specification. Suppose A is regular fit and B is oversized. The team should decide whether the silhouette difference is welcome before ordering a large decorated trial. If not, request a more comparable cut rather than declaring the lighter or heavier fabric the winner.
Finally, collect specific observations: acceptable alone, comfortable under the intended layer, preferred sleeve shape and acceptable print feel. If both candidates pass, the store could offer a regular everyday tee and a substantial relaxed tee with honest descriptions. If only A fits the use case, choosing it is not automatically a budget compromise. If employees prefer B’s intended look, its heavier fabric can be a deliberate feature.
Keep a weight decision record that survives substitutions
The value of a sample disappears if the final order can silently change to a different garment. Put the approved decision into the purchase brief or product record:
- Identity: manufacturer, style number, regional version and approved color.
- Fabric: composition, construction and nominal weight with units.
- Fit: named silhouette, size chart and any approved companion styles.
- Use: layering, standalone wear, work context or recipient-choice role.
- Decoration: method, placement, dimensions and approved sample reference.
- Evidence: specification source, review date and retained sample location.
- Change rule: who must approve a different style, fabric specification or color.
Do not invent a tolerance such as “plus or minus 5% is acceptable” merely because it sounds technical. If mass per area is a contractual acceptance criterion, agree the tolerance, sampling approach and test method with the supplier before purchase. ASTM D3776/D3776M-20(2025) covers fabric mass-per-area testing. Its public summary distinguishes sampling options and cautions that small-swatch results apply to that sample, not necessarily its entire originating lot.
That distinction gives a buyer a sensible escalation path. A nominal specification may be enough for an ordinary gift shortlist. A disputed production lot or tightly specified uniform order may justify professional testing. A kitchen-scale reading of an intact shirt is not a substitute for an agreed fabric-testing procedure.
Match the purchasing model after approving the product
Fabric weight does not determine whether bulk, on-demand or hybrid production is the right buying model. Bulk can make sense when the approved garment, quantities and size mix are known and a coordinated issue date matters. On-demand can suit recurring orders or recipient choice when the exact approved product and decoration are available through that route. A hybrid can reserve a core issue garment while keeping optional gift choices separate.
Ask for the actual decorated quote, sample charges, freight and any minimum quantities. Do not estimate shipping from GSM alone: the packed shipment is what matters. Equally, do not assume that a heavier garment always commands a higher total program cost or that on-demand will be cheaper. Use the same approved specification when applying the on-demand versus bulk comparison.
Frequently asked questions
Is 220 GSM always better than 180 GSM?
No. It describes more mass per equal fabric area. The better purchase is the garment that meets the fit, wearing, decoration and care requirements. A higher number cannot settle those decisions by itself.
Can I convert the weight of a finished shirt into GSM?
Not from that weight alone. You would also need appropriate fabric-area information and would have to account for the garment’s different components. Request the manufacturer’s fabric specification instead.
What if the quote lists ounces without “per square yard”?
Ask the supplier to identify the unit and what was weighed. Do not apply the conversion formula until you know it is an areal fabric measurement, rather than a finished-item or packed weight.
Should every shirt in a company store have the same GSM?
Not necessarily. Consistent product roles and clear descriptions are more useful than forcing different garments to share one number. Preserve the approved specification for each style, and require review when a replacement changes the intended experience.
