GSM is the single most misread spec in the shade net market — buyers order by it as if it were the shading rate, then discover their “90 gsm” net tells them nothing about how much sun it blocks. The direct answer: GSM is fabric weight (grams per square meter), not shading. It tells you how much polymer is in the net — which decides tear strength, outdoor lifespan and price — while the knit structure decides the shade percentage. Pick GSM by how long and how hard the net must work, not by how dark you want it. Here is how to choose, with the numbers we use when specing orders from our knitting lines in Changzhou.
Shade rate (30%, 50%, 70%, 90%) is set by the knit structure — how densely the tapes interlock. GSM is set by how much HDPE goes into each square meter. The same 70% shade net can be knitted at 60 gsm for a season of greenhouse use or at 135 gsm for a decade of nursery duty — identical shade, completely different durability and price. This is why “what GSM is 70% shade net?” has no single answer, and why quotes from two factories at the same shade rate can differ by 40%: they are silently quoting different weights. When you compare prices, always compare price per kg at a stated GSM, never price per roll.
| Application | Typical GSM | Why |
|---|---|---|
| Garden & seasonal vegetable cover | 40–60 | One to two seasons, light handling, economy first |
| Greenhouse roof & side shading | 60–90 | Multi-season exposure, tensioned spans, regular re-hanging |
| Nurseries & permanent shade houses | 100–135 | Years of continuous outdoor duty over valuable stock |
| Orchard & vineyard shading structures | 90–135 | Wind exposure plus seasonal install/removal cycles |
| Car parking & heavy-duty canopies | 180–280 | Permanent tensioned structure in full weather |
| Privacy & wind-screen duty | 150–350 | Maximum density, blockage and durability |
Our knitting range covers 40–350 gsm across shade rates 30–90%, so any cell in that table can be combined with the shade percentage your crop needs. The shade-rate side of the decision is covered in our shade percentage guide — this article is deliberately only about weight.
One caveat before comparing GSM numbers between suppliers: the same weight means different things in different constructions. A monofilament knit puts its polymer into round yarns — better tear resistance and longer life per gram; a tape knit puts it into flat ribbons — more shade per gram and a softer drape, but lower tear strength at the same GSM. A 90 gsm monofilament net and a 90 gsm tape net are not the same product. The full construction comparison is in our monofilament vs tape netting guide; when we quote, we state both the GSM and the construction so the comparison is honest.
The economics of GSM surprise most first-time buyers. Example from our order history: a 60 gsm greenhouse net at commodity UV levels typically serves 1–2 seasons before the fixing points fail; a 135 gsm net with our standard UV package serves 5+ seasons in the same position. Per season of service, the heavy net costs roughly half — before counting the labor of re-hanging. The rule we give distributors: if the net comes down every season anyway, buy light; if it stays up, buy heavy. And whatever the weight, insist on 100% virgin HDPE — recycled regrind at any GSM chalks and tears early, which is how “cheap 120 gsm” nets end up performing like 60 gsm.
GSM is the easiest spec to check and the most commonly cheated, so check it. Cut a full-width 1 m length from a roll, weigh it on a bench scale, and divide by the roll width — that is your actual grams per square meter. Weigh three rolls from different pallets, not one. A honest tolerance is ±5%; a “135 gsm” net measuring 112 is a different product than the one you ordered, and you should raise it while the container is still in your yard. This is exactly why we weigh-check inline during knitting and keep retention samples per container — if the numbers ever disagree, both sides can test the same material. Any supplier who cannot tell you the GSM tolerance before you order is telling you something.
Because netting is polymer by the kilogram, GSM is also your logistics number. A 40’HQ carries 14–15 tons — at 60 gsm that is roughly 230,000 m² of net; at 135 gsm roughly 105,000 m². Same container, same freight, half the square meters — which is why heavy-duty programs should always be quoted landed cost per m², not per ton. Our MOQ is 2 tons with mixed GSM, shade rates and colors in one container; production runs 25–35 days after deposit; samples of any weight are free, you cover the courier. Send your application, target shade rate and expected service years via the contact page or WhatsApp and we will recommend a GSM with roll counts and loading math within 24 hours.
No — higher GSM is heavier, stronger and longer-lasting, but it is also stiffer, harder to handle and up to twice the price per square meter. Match weight to duty: seasonal covers want 40–60 gsm, permanent structures want 100 gsm and up. Overspecing weight wastes money every season.
Not directly. Shade percentage comes from the knit structure, not the weight — a 60 gsm and a 135 gsm net can deliver the identical 70% shade rate. Within the same construction, heavier variants block marginally more light, but you should choose shade rate first and GSM separately.
60–90 gsm for most commercial greenhouses: light enough to handle and re-hang, heavy enough for multi-season tensioned exposure. Go to 100–135 gsm only for permanent shade-house structures or very windy sites.
With a proper UV-stabilizer package on virgin HDPE: 1–2 seasons at 40–60 gsm, 3–5 years at 80–100 gsm, 5+ years at 135 gsm and above — assuming the net stays installed. Seasonal removal and dry storage roughly doubles practical life at any weight.
Usually one of three reasons: recycled regrind instead of virgin HDPE, a lower UV-stabilizer dose, or a different construction (tape vs monofilament) presented as equivalent. Ask for the material declaration and UV test report by batch — it separates real GSM from nominal GSM.
Choose shade rate by crop, GSM by duty: 40–60 gsm seasonal, 60–90 greenhouse, 100–135 permanent, 180+ parking and privacy. Tell us the application and service years you need and we will spec the weight — and show you the same decision on the actual shade net knitting lines.
Quick Inquiry
Tell us the product and requirement — we reply within 24 hours.
Prefer WhatsApp? +86 152 6119 9768