Key takeaways

• GSM means grams per square metre: the weight of the fabric.
• Our bags range from 45 GSM for light D-cut and W-cut bags to 130 GSM for packaging bags.
• Handles, seams and construction matter as much as GSM; most bags fail at handle joints.
• Choose the lightest GSM that safely carries your load with a margin, then test a sample.
• Laminated GSM includes the film layer: 105 GSM for two layers, 120 GSM for three.

Introduction

When you ask for a quotation for non-woven bags, one of the first questions you will hear is: “What GSM do you need?” For many buyers, it is also one of the most confusing. Should a shopping bag be 60 GSM or 100 GSM? Is a heavier bag always better? Why does GSM change the price so much?

GSM is simply a measure of fabric weight, but it affects almost everything about a bag: how strong it is, how it feels in the hand, how well it holds its shape, how long it lasts and how much it costs. Choosing the right GSM means getting a bag that does its job without paying for strength you do not need.

This guide explains what GSM means, the GSM ranges used for different bag types, how GSM interacts with bag construction and lamination, how to match GSM to the load, how GSM affects cost and how to test bags before a large order. It ends with an illustrative example and answers to common questions.

What GSM means

GSM stands for grams per square metre. It is the weight of one square metre of fabric. A 60 GSM fabric weighs 60 grams per square metre; a 120 GSM fabric weighs twice as much.

For non-woven polypropylene fabric, a higher GSM generally means:

• thicker fabric, which feels more substantial;
• more strength, especially resistance to tearing and stretching;
• better shape, so bags stand up and look fuller;
• better print appearance, because thicker fabric shows less show-through; and
• higher material cost, because more polypropylene is used.

GSM is not the only factor in a bag’s strength. Construction, handle design and how seams are sealed also matter, as this article explains.

GSM ranges in our bag range

For loop handle, box and stitched bags, we choose the GSM to suit the load, size and finish you need.

A general guide to non-woven GSM

Across the industry, non-woven bag fabric is commonly grouped as follows:

These are guidelines, not rules. A well-made 80 GSM bag can outperform a badly made 100 GSM bag.

Why construction matters as much as GSM

A bag usually fails at its weakest point, which is rarely the middle of the fabric. Most failures happen at:

• handle joints, where the handle meets the bag body;
• the edges of D-cut handle holes;
• seams, especially at the base; and
• corners of box bags, where stress concentrates.

That is why construction choices matter:

• Reinforced D-cut handles spread the load around the handle hole.
• Stitched handle joints are stronger than welded joints for heavy loads, which is why our stitched bags carry up to 20 kg.
• Box construction with a gusset and flat base spreads weight more evenly than a flat bag.
• Lamination adds a film layer that increases strength and stiffness.

When choosing GSM, think about the whole bag, not just the fabric.

Laminated GSM explained

Laminated bags have more than one layer: non-woven fabric plus a laminated film. Their GSM therefore includes both layers. Our ready-design laminated bags, for example, are 105 GSM with two layers and 120 GSM with three layers. Because the film adds strength and stiffness, a laminated bag can often carry more than an unlaminated bag of similar fabric weight, and it holds its shape better.

Matching GSM to the load

Start with the heaviest load a customer is likely to carry, then choose the bag type and GSM:

Always allow a safety margin. If customers might carry 5 kg, choose a bag rated for more.

GSM and the customer's impression

Weight is not only about strength. Customers judge quality by touch. A thin bag can feel cheap, even if it is strong enough, while a heavier or laminated bag feels substantial and premium. For high-value purchases, such as jewellery, textiles and gifts, a heavier GSM or a laminated, metallic or shimmer finish sends the right message about your brand.

GSM, colour and printing

Fabric weight also interacts with colour and printing. On very light fabric, dark inks can show through to the other side, and fine details may look less sharp because the surface is more open. Medium and heavier fabrics give a smoother, more solid surface, so logos and text look crisper. For full-colour photographs, laminated fabric gives the best result regardless of the base GSM, because the image is printed on a smooth film.

Colour can also affect how customers perceive weight. Deep colours such as navy, black and maroon often make a bag look more substantial, while very pale fabrics can make thin bags look thinner. If you are choosing a lighter GSM to control cost, a richer fabric colour and a bold, simple print can help the bag still look professional.

GSM and cost

Fabric is one of the largest costs in a non-woven bag, so GSM has a direct effect on price. Doubling the GSM roughly doubles the fabric used per bag. But choosing too light a GSM can cost more in the long run, if bags tear, customers are disappointed or bags are thrown away instead of reused.

Ways to balance strength and cost:

• choose the lightest GSM that safely carries your typical load, with a margin;
• use reinforcement or stitching at handle joints instead of increasing GSM everywhere;
• use laminated bags where you need both strength and a premium look;
• standardise sizes, so you can order larger quantities of fewer specifications; and
• reserve heavy, premium bags for the purchases that need them.

Testing bags before a large order

Before ordering thousands of bags, test a sample:

1. Load test. Fill the bag with the heaviest load customers will carry, plus a margin, and lift it by the handles several times.
2. Swing test. Carry the loaded bag and swing it gently, as customers do when walking.
3. Repeat test. Load and unload the bag several times to simulate reuse.
4. Edge test. Check handle joints, D-cut edges and base corners for stretching or tearing.
5. Feel test. Ask staff and a few customers how the bag looks and feels.

If a sample struggles, increase the GSM, add reinforcement, switch to stitched construction or choose a different bag type.

How GSM is measured

Measuring GSM is simple. A sample of fabric is cut to a known area, often a circle of 100 square centimetres using a special cutter, and weighed on an accurate balance. The weight is then multiplied up to give grams per square metre. For example, if a 100 cm² sample weighs 0.8 grams, the fabric is 80 GSM.

Because fabric weight can vary slightly across a roll, several samples are usually tested and averaged. Checking GSM on incoming fabric is one of the first quality checks in bag production, because fabric lighter than specified produces weaker bags.

Other fabric properties that matter

GSM is the most quoted specification, but other properties also affect performance:

• Tensile strength: how much pulling force the fabric withstands before it breaks, measured along the roll (machine direction) and across it (cross direction).
• Elongation: how much the fabric stretches before it breaks. Some stretch helps absorb shocks; too much makes handles sag.
• Uniformity: even fabric has no thin patches where tears can start. Good spunbond fabric has a consistent web without visible thin areas.
• Bonding pattern: the dotted pattern from the heated calender rollers holds the fibres together; good bonding prevents fuzzing and pilling.
• UV stability: polypropylene can weaken with long exposure to strong sunlight. Bags stored or displayed in direct sun for long periods may age faster.

Good manufacturers check these properties, not just GSM, when choosing fabric.

GSM in Sri Lankan conditions

Local conditions also influence the choice:

• Rain and humidity: in the monsoon seasons, laminated bags keep purchases drier and are easier to wipe clean.
• Heat and sunlight: bags left in hot cars or in the sun for long periods can weaken over time; heavier, laminated fabrics generally cope better with rough use.
• Heavy shopping habits: many families buy rice, vegetables and household goods in one trip, so supermarket bags often need more strength than fashion bags.
• Festive peaks: bags used for festive shopping and gifts often carry heavier, bulkier items, so a stronger option is worthwhile at those times.

GSM and reuse

A reusable bag only delivers its environmental benefit if it is actually reused. Heavier bags use more material to make, so they need to be reused more times to make up for that extra material compared with a lighter bag. But heavier, well-made bags also last much longer and are more likely to be kept and reused.

The best choice is a bag strong enough for many trips, attractive enough that customers want to keep it, and no heavier than it needs to be. Blog Article 3 looks at reuse and the environment in more detail.

A step-by-step GSM decision guide

1. Identify the typical and heaviest load your customers carry.
2. Choose the bag type that suits the item: D-cut, W-cut, loop handle, box, stitched or packaging.
3. Decide on the finish: plain non-woven, laminated, PP woven, metallic or shimmer.
4. Pick a starting GSM from the guide tables in this article.
5. Check construction: reinforced handles, welded or stitched seams, gusset and base.
6. Order a sample and test it with real loads.
7. Adjust GSM, construction or bag type if needed.
8. Confirm the specification in writing so repeat orders are identical.

GSM suggestions by business

These suggestions show how different businesses typically balance strength, feel and cost. Your final choice should be confirmed with a sample.

Questions to ask your bag supplier about GSM

• What GSM do you recommend for my typical load, and why?
• Is the GSM quoted for the fabric alone, or including lamination?
• How are the handles attached, and are the joints reinforced?
• What load has this bag been tested to carry?
• Can I have samples in two different GSMs to compare?
• Will repeat orders use exactly the same GSM and construction?

A good supplier will explain the recommendation, not just quote a number.

Common GSM mistakes

• Choosing by price alone. The cheapest GSM may not carry your customers’ purchases.
• Ignoring handles. Heavy fabric with weak handle joints still fails.
• Over-specifying. Paying for 120 GSM bags to carry jewellery boxes wastes money.
• Using one bag for everything. Many businesses need two or three bag types and GSMs.
• Not testing. A quick sample test prevents costly mistakes.

An example in practice

The following example is illustrative and does not describe a real customer.

A grocery shop has been using thin 50 GSM W-cut bags, but customers complain that the handles stretch and tear with heavier items. We test the shop’s typical baskets and find that many weigh 5–7 kg. We recommend two bags: 80 GSM W-cut bags for small baskets, and stitched bags with reinforced handles for larger shops of 10 kg or more.

After testing samples with the shop’s staff, the shop orders both. Complaints stop, and many customers start bringing the stitched bags back for weekly shopping, carrying the shop’s logo around the neighbourhood.

Frequently asked questions

What does GSM stand for?

Grams per square metre. It measures the weight of the fabric.

Is a higher GSM always better?

Not always. Higher GSM is stronger and feels more premium, but it costs more. Choose the lightest GSM that safely carries your load, with a margin.

What GSM is best for a supermarket bag?

For lighter groceries, 70–90 GSM W-cut or loop handle bags work well. For heavier shopping, choose stitched bags or laminated box bags.

What GSM are your packaging bags?

Our non-woven packaging bags are 130 GSM.

Does lamination increase GSM?

Yes. Laminated bags include the weight of the film layer. Our ready-design laminated bags are 105 GSM (two layers) or 120 GSM (three layers).

Can I see different GSM samples?

Yes. We can show fabric samples and sample bags in different GSMs so you can compare.

Why do some bags of the same GSM feel different?

Fabric uniformity, bonding pattern, lamination and colour all change how a bag feels. Construction also matters: a box bag with a gusset feels sturdier than a flat bag of the same GSM.

Will a heavier GSM make printing look better?

Often, yes. Thicker fabric shows less show-through and gives a smoother printing surface, and laminated bags give the brightest results.

Can I use different GSMs for different bag sizes?

Yes, and it often makes sense. Small bags for light items can use a lighter GSM, while large bags for heavy purchases use a heavier GSM or stitched construction. Keeping the same artwork and colours across sizes gives a consistent brand look.

Conclusion

GSM measures fabric weight, and it influences strength, feel, shape and cost. But the right bag depends on more than GSM: handles, seams, construction and lamination all play a part. Start with the load, choose the bag type, pick the lightest GSM that safely carries the load with a margin, and test a sample before ordering in quantity.

Need help choosing GSM? Ask us for samples and advice.

Ask for GSM Samples

Related reading

• How Non-Woven Bags Are Made: From Polypropylene to a Printed, Branded Bag
• Designing a Custom Printed Non-Woven Bag: Size, Strength, Artwork and Ordering
• Non-Woven Bag Types Guide: D-Cut, Loop Handle, W-Cut, Box, Stitched, Laminated, Metallic, Packaging and Thermal Bags
• Printing Methods for Branded Non-Woven Bags: Screen, Flexo, Rotogravure and Offset Compared
• Non-Woven, Paper or Plastic: Which Bag Wins?
• See all non-woven bags

Sources

• Product specifications from the owner's bag catalogue (GSM ranges and load capacities)
• CXGIAE, PP non-woven bags: a complete guide for wholesale buyers (GSM ranges and uses): https://cxgiae.com/blog/pp-non-woven-bags-a-complete-guide-for-wholesale-buyers/
• BK Bags, PP non-woven bags (typical GSM for promotional and heavy-duty bags): https://bk-bags.com/shop/pp-non-woven/
• THE RPS LLC, non-woven bag printing supplier (GSM options): https://therpsllc.com/product/non-woven-bag-printing-supplier-dubai/