How to choose GSM for a 50 kg bag
Fabric weight decides whether a sack survives handling — or splits on the loading dock. A practical guide for buyers.
GSM — grams per square metre — is the single number that decides how strong a PP woven bag is. Too light and the sack tears under a 50 kg load or on rough handling; too heavy and you pay for material you did not need. Getting it right is mostly about matching the fabric to what goes inside and how the bag is treated.
What GSM actually controls
A higher GSM means more tape, tighter weave, and a stronger, stiffer bag. That buys you tensile strength, resistance to tearing at the seams, and better stacking. But weight is not free — it is the biggest driver of the per-bag cost, so the goal is the lowest GSM that comfortably carries and protects your product.
A rule of thumb for 50 kg
For a 50 kg sack, fabric is commonly specified somewhere in a broad band — lighter for free-flowing, forgiving fills and heavier for dense, sharp, or roughly handled products. Cattle feed, cement, and fertilizer that get thrown and stacked high sit at the heavier end; flour and grains that are palletised carefully can run lighter. The honest answer is that the right number depends on the fill density, the drop and stacking it will see, and whether the bag is laminated.
Fabric quality, not just GSM
On the floor we usually talk in a fabric quality number rather than raw GSM — it is the same idea expressed the way the trade orders it. A higher quality number is heavier, stronger fabric. When you brief us, you can give either: a target GSM, a quality number, or simply the product, bag size, and how it is handled, and we will spec the fabric to match.
- Denser or sharper fill → step up the fabric weight.
- Rough handling, high stacking, long transit → step up.
- Laminated bag → the lamination adds strength and a moisture barrier.
- Careful, palletised handling → you can often step down and save cost.
Not sure where to land? Tell us the product, the bag size, and how it moves. We will recommend a fabric weight, and every order is confirmed against your exact spec before it runs.
Have a bag in mind? Spec it and we'll quote it.
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