GSM

What is GSM in fabric? GSM means grams per square meter (g/m² or g/m2): the mass of one square meter of cloth. On a purchase order it is the usual fabric weight field—not a yarn count and not a quality grade by itself. Write the unit and the process stage (greige vs finished) so “110 GSM” cannot be read two ways.

Spelled out: grams per square meter (or metre)

The unit is written out far more often than the acronym. Four forms appear in buyer documents, and all four mean the same thing:

gram per meter square and other reorderings are the same unit written incorrectly. If a spec says gram per square meter rather than grams, the number is still grams per square meter — the singular is a typographic habit, not a different measure.

Plain-language example

If a sheet is 110 GSM, one square meter of that cloth weighs 110 grams. Higher GSM usually feels heavier or denser within the same construction family; it does not automatically mean “better quality” across unrelated weaves or finishes.

Related but different: denier describes yarn linear density, not fabric area weight. Thread count describes yarn density in the weave plan—not grams per square meter. Use GSM with those fields on the PO.

01

Lighter neighborhood

Sheers and light bedding often sit lower. Still write the number.

02

Mid-weight neighborhood

Many bedding and lining programs live here. GSM is still a field, not a grade.

03

Heavier neighborhood

Curtain and upholstery bases often sit higher. Opacity is not GSM by itself.

GSM vs denier (do not swap them)

A fine yarn can still make a heavy cloth if the sett is dense. A coarse yarn in an open sett can be lighter. Write both.

How GSM is measured

Labs and QC rooms use a fixed area, a scale, and simple arithmetic so results are comparable:

1. Cut a known area (often 10 cm × 10 cm = 100 cm²), or use a GSM cutter that punches that area.
2. Weigh the sample on a precision scale.
3. Convert to g/m² (for a 100 cm² sample, multiply grams by 100):

GSM = Sample Weight (g) × 100

Example: A 10×10 cm cut weighs 1.05 g → 1.05 × 100 = 105 GSM.

Prefer a worked walkthrough with unit conversion? See how to calculate fabric GSM.

New to the term? What is GSM in fabric covers it in plain language, including why the bare acronym also means the mobile network standard.

Test more than one place on the roll when the program is sensitive to variation. Finishes (coating, softener pick-up, calendering compression) can move the number relative to greige—so state whether the GSM is greige, after prep, or finished.

GSM to oz (ounces per square yard)

US and some home-textile buyers still talk oz/yd² (ounces per square yard) while most international mills quote GSM. A practical conversion many trade sheets use:

GSM ≈ oz/yd² × 33.906

oz/yd² ≈ (GSM) ÷ (33.906)

Example: 110 GSM ≈ 110 / 33.9 ≈ 3.2 oz/yd². Write the unit your counterparty uses, and freeze one primary number on the PO so rounding does not become a dispute.

GSM to oz/yd² chart

These are the conversions that get asked for on a PO or a tech pack. The last column is oz/yd² rounded to two decimals—name it as a figure, not as a lab result.

Reading it back the other way, for a spec that arrives in ounces:

A 4 oz/yd² cloth is a 136 GSM cloth—close enough that a PO that says “4 oz” without a tolerance will be read two ways. Quote the GSM as the primary number and the ounce as the converted figure.

Typical ranges (illustrative)

These bands are common industry neighborhoods, not pass/fail limits. Confirm against the end-use and your lab method:

Within one construction family, higher GSM usually means more fiber per area—and often more raw-material cost—but “better” still depends on hand, drape, opacity, and durability targets.

What drives GSM

• Fiber density and yarn count — denser fibers or coarser yarns raise weight at the same sett.
• Sett / construction — more ends and picks per inch pack more mass into the square meter.
• Weave — twill and other structures can pack differently from plain weave at similar counts.
• Finish — coatings and some resins add weight; some mechanical steps can slightly reduce it.

Pair GSM with denier, yarn count, width, and weave on the PO so the mill and the buyer are not arguing from different pictures of the same cloth.

What to put on the purchase order

• Target GSM and an agreed tolerance (or “as mill standard sample”).
• Whether the number is greige, after preparation, or after finish (wet process and finish change weight and width).
• Width, fiber, weave, and finish route in the same line of specs.
• How disputes will be sampled (location on the roll, number of cuts).

Mill greige context

On Weaverine greige polyester programs, common stock specs sit roughly in the 55–120 GSM range at 160–330 cm widths (plain and twill constructions). Use the product page for commercial widths, stock MOQ, and quote requests—not this glossary page—when you are buying loom-state cloth.

For stage language (greige vs prepared bases), see greige fabric and PFD.