Guide GSM : comment choisir le grammage de papier adapté aux emballages industriels

GSM (grams per square metre) is the primary specification parameter for industrial packaging paper, but choosing the right GSM is not as simple as picking a number — it depends on the application, the fill weight, the required burst and tensile strength, the converting process, and the service environment. This guide maps 14 industrial packaging applications to their recommended GSM paper ranges and the key performance properties that drive the selection.

GSM Application Guide: 14 Industrial Packaging Uses

The table below maps common industrial packaging applications to recommended GSM ranges, material types, and the key performance requirement that drives the specification.

What GSM Is and How It Is Measured

GSM (grams per square metre), also written g/m², is the universally recognised metric measure of paper and board weight. It is measured by cutting a standardised test piece (most commonly 100 mm × 100 mm = 0.01 m²) from the paper, weighing it to the nearest 0.001 gram on a calibrated analytical balance, and multiplying by 100 to get the mass per square metre. The measurement is typically taken at multiple points across the roll width and along the roll length, and the result is reported as the average with a stated ± tolerance (typically ±3–5% for kraft paper).

GSM is a mass measurement, not a thickness measurement. Two papers of identical GSM can have different thicknesses (and therefore different caliper) depending on how densely the fibres are packed. A highly calendered (rolled) papier kraft is denser and thinner than an uncalendered paper at the same GSM. Caliper is expressed in µm (micrometres) or mm and is measured using a calibrated micrometer at defined contact pressure (typically 100 kPa for paper). Specifying both GSM and caliper — or GSM and density — gives more complete definition of the paper structure than GSM alone.

For technical specifications, GSM should always be combined with key mechanical property callouts. The most important are: tensile strength MD and CD (kN/m, per ISO 1924-2), burst strength (kPa Mullen or hydraulic, per ISO 2759), elongation at break MD (%, per ISO 1924-2), and Cobb water absorption (g/m² at 60 seconds, per ISO 535). These four properties define the functional performance of the paper far more precisely than GSM alone.

• GSM is measured per ISO 536: cut 0.01 m² test piece, weigh, multiply by 100
• Typical GSM tolerance on kraft paper: ±3–5% of nominal (so 90 gsm ±4.5 gsm in production)
• GSM is mass per unit area — not thickness. Specify caliper separately if thickness matters for your converting process
• Always combine GSM with key property callouts: tensile, burst, elongation, Cobb water absorption

Understanding the Paper Grammage Range: From 17 gsm to 440 gsm

Industrial paper products span an enormous GSM range. At the low end, tissue paper (17–25 gsm) is the thinnest commercially produced paper, with individual fibres nearly visible to the naked eye. At the high end, heavyweight kraft liner board (350–440 gsm) is thick enough to be classified as paperboard rather than paper. The industrial packaging range — 30–200 gsm — covers the vast majority of bag, wrapping, interleaving, and specialty paper applications.

Within this range, the GSM selection is primarily driven by the mechanical load the paper must carry. Wrapping paper used only to protect a surface from scratching during transit needs only 30–50 gsm — the paper needs to be clean, smooth, and non-abrasive, not structurally strong. Paper used as the outer ply of a 50 kg cement bag must withstand internal bag pressure during filling, drop impact during handling, and stack compression during palletised storage — this application demands 90–100 gsm virgin extensible sack kraft with burst strength above 400 kPa and elongation above 10% MD.

Tissue and Light Interleaving Paper: 17–60 gsm

Tissue paper (17–25 gsm) is produced on tissue machines that create a crinkled, soft surface by creping the paper against a Yankee dryer. The result is a low-density, high-bulk paper with a soft texture. In packaging, tissue is used for delicate product wrapping in premium retail, cosmetics, and fashion, where the customer perceives the tissue wrapping as part of the brand experience. Tissue should be specified for applications where softness, no abrasion, and visual appeal are the primary requirements — not where structural strength matters.

Interleaving paper (30–60 gsm) is a different application — here the functional requirement is chemical neutrality and surface protection, not softness. Glass interleaving paper must be free of surface particles that could scratch polished glass surfaces. Electronics interleaving paper must have sulfur content below 50 ppm to avoid tarnishing silver contacts and PCB traces. LED and solar cell interleaving must meet defined silicone contamination limits. These are technical performance specifications that the paper supplier must verify by laboratory testing on each production lot. Kangchuang Papers provides sulfur-free interleaving paper with lot test reports confirming sulfur content and surface particle analysis. See Kangchuang Papers’s full product range for available interleaving grades.

Standard Wrapping and Light Bag Paper: 50–90 gsm

The 50–90 gsm range covers the largest volume segment of the industrial kraft paper market: wrapping paper for hardware and industrial goods, single-ply retail bags for bakery and grocery, and the inner plies of multi-wall bags for food and agricultural products. At 60–70 gsm, virgin kraft paper provides adequate tensile strength for single-ply retail bags with fills up to 5 kg. At 80–90 gsm, the burst strength (typically 220–320 kPa for virgin kraft at this weight) is sufficient for single-ply bags with fills to 10 kg and for the outer ply of multi-wall bags with lighter fills.

The choice between virgin and recycled kraft in this range depends on the fill weight and drop requirement. Recycled kraft at 80 gsm achieves burst strength of approximately 150–220 kPa — adequate for light-fill bags (up to 5 kg) but insufficient for medium fills. Virgin kraft at the same GSM achieves 250–320 kPa, comfortably handling fills to 10 kg. If the application requires medium fill weight with cost-sensitive material, a high-quality recycled kraft at 90–100 gsm can approach the performance of virgin kraft at 80 gsm, though elongation at break remains lower with recycled fibre.

Heavy-Duty Industrial Sack Paper: 90–120 gsm

Above 90 gsm, kraft paper enters the heavy-duty industrial sack range: materials for cement bags, chemical powder bags, agricultural bulk bags, and mineral product sacks that must withstand fills of 20–50 kg and drop tests from 1.2 metres onto concrete. At this performance level, virgin extensible sack kraft is essentially the only option. Extensible kraft is manufactured by compressing the paper in the machine direction during production, creating a crinkled microstructure that allows controlled elongation at break of 8–14% MD. This elongation absorbs the kinetic energy of a drop impact progressively, preventing catastrophic burst failure.

Kangchuang Papers produces virgin sack kraft from 70 to 150 gsm with lot test reports confirming tensile, burst, elongation, and Cobb water absorption on every production lot. MOQ 500 kg for standard grades; custom GSM specifications from 3 tonne run minimum. Visit kangchuangpapers.com to request grade specifications and a sample roll for technical evaluation.

Release Liner and Specialty Base Papers: 60–120 gsm

Release liner base paper (also called SCK — super calendered kraft) is a highly smoothed kraft paper that serves as the carrier for silicone coating in pressure-sensitive label and tape applications. The silicone is applied to the super calendered surface, cured, and then a pressure-sensitive adhesive is laminated against the silicone release surface. When the label or tape is applied by the end user, the release liner is stripped away. The key performance requirements for release liner base paper are: extremely smooth surface (Ra ≤ 1.0 µm, measured by profilometry), consistent caliper (very low caliper variation for winding and converting), and adequate silicone anchorage (the silicone coating must adhere to the paper surface strongly enough that it stays with the liner when the adhesive is stripped away, not with the tape).

VCI (Vapour Corrosion Inhibitor) kraft paper is impregnated with a volatile corrosion inhibitor compound that vaporises slowly at ambient temperature, filling the enclosed space around a metal part with a corrosion-inhibiting atmosphere. VCI kraft is used for wrapping machined metal parts, tools, and instruments during shipping and storage. The key specification for VCI kraft is the inhibitor emission rate (typically measured as mg inhibitor per square metre of paper) and the coverage area (how much metal surface area one square metre of VCI paper will protect at the specified storage duration).

Corrugated Liner Board: 125–250 gsm

Corrugated liner board (the outer and inner facing sheets of corrugated boxes) is at the upper end of the paper weight range, technically classified as paperboard rather than paper above approximately 200 gsm. The primary structural property for corrugated liner is Ring Crush Resistance (RCT, measured in kN/m per ISO 12192), which governs how much vertical compressive load the corrugated box can sustain in a stacking configuration. Higher GSM liner generally provides higher RCT, but the correlation is not linear — liner produced from long-fibre virgin kraft achieves higher RCT per unit GSM than liner from recycled OCC furnish.

How to Write a Complete Paper Specification

A complete industrial paper specification includes: paper type (virgin kraft, recycled kraft, SCK, tissue); GSM nominal value with ± tolerance; tensile strength MD and CD (kN/m); burst strength (kPa, test method); elongation at break MD (%) for sack applications; Cobb water absorption (g/m² at 60 seconds); moisture content (%); and any specialty requirements (sulfur content ppm for electronics, silicone contamination limit for LED/glass, VCI inhibitor emission rate). Roll format specifications: roll width (mm), core diameter (mm or inches), and maximum roll diameter (mm) for compatibility with your converting equipment. Kangchuang Papers can produce to any of these specifications — contact the technical team via kangchuangpapers.com to discuss your specific application requirements.

Conclusion

GSM is the starting point for industrial paper specification, not the endpoint. The right paper for your application is defined by its combination of GSM, fibre type, strength properties, surface characteristics, and any specialty functional requirements. Use the application guide in this article to establish the right GSM range, then work with your paper supplier to specify the strength properties that ensure the paper performs reliably in your packaging system. For custom kraft paper grades from 35 to 150 gsm with full technical documentation and 500 kg MOQ, contact Kangchuang Papers to request specifications and samples.

Foire aux questions

Que signifie « GSM » dans le domaine du papier ?

GSM stands for grams per square metre — it is the mass of one square metre of paper in grams. GSM is the universal measurement of paper weight used globally in the paper industry and in packaging specifications. A 70 gsm paper weighs 70 grams per square metre. GSM directly correlates with paper thickness and density, which in turn determines the paper’s strength properties. Higher GSM generally means more material, greater burst strength, higher tensile strength, and better moisture resistance, though the specific properties also depend on fibre type and manufacturing process.

Quelle est la différence entre le grammage et le GSM ?

Le grammage de base est l'unité de mesure traditionnelle américaine du poids du papier, exprimée en livres (lbs) par ramette (500 feuilles) d'un format de feuille de référence spécifique qui varie selon le type de papier. Le format de référence pour le papier bond diffère de celui du papier de texte ou du papier de couverture, ce qui rend les comparaisons de grammage entre les différents types de papier peu claires. Le GSM (grammes par mètre carré) est l'équivalent métrique et s'applique de manière uniforme à tous les types de papier : un mètre carré de n'importe quel papier dont le GSM est indiqué pèsera exactement ce nombre de grammes. Pour convertir le grammage américain en GSM pour le papier kraft ou d'emballage, il suffit de multiplier le grammage par 1,48.

Quel est le grammage habituel des sacs en papier kraft ?

Les sacs en papier kraft à simple épaisseur destinés à la vente au détail (sacs de courses, sacs à sandwich, sacs en papier pour le vin) sont généralement fabriqués à partir de papier kraft vierge ou recyclé de 60 à 90 g/m². Les sacs industriels à parois multiples (pour le ciment, la farine, les poudres chimiques) utilisent entre 70 et 100 g/m² par couche, avec 2 à 4 couches selon le poids du contenu et les exigences en matière de résistance aux chocs. Les sacs à simple paroi très résistants destinés à des charges moyennes (10 à 25 kg) nécessitent du papier kraft vierge de 90 à 120 g/m². Pour les charges supérieures à 25 kg (ciment, poudres minérales), la norme est du papier kraft extensible de 80 à 100 g/m² par couche, dans une configuration à parois multiples.

Quelle épaisseur en papier d'intercalation faut-il utiliser pour protéger un panneau en verre ?

Le papier intercalaire utilisé pour le verre plat, les panneaux LED, les cellules solaires et les composants optiques de précision présente généralement un grammage compris entre 30 et 60 g/m². Les exigences spécifiques dépendent de la sensibilité de la surface du produit : le verre hautement poli nécessite un papier intercalaire de type papier tissu, plus doux et de grammage inférieur (17 à 30 g/m²), avec une taille maximale définie des particules et une teneur en soufre nulle. Le verre flotté standard et le verre architectural utilisent un papier intercalaire kraft de 40 à 60 g/m². Pour les plaquettes de silicium et les puces LED, un papier intercalaire sans soufre, dont le grammage et les limites de contamination au silicone sont définis selon les spécifications du client, est requis.

Un GSM plus élevé signifie-t-il toujours que le papier est plus résistant ?

Pas toujours. Le grammage augmente avec la quantité de fibres par mètre carré, ce qui améliore généralement la résistance à la traction et à l'éclatement. Mais la résistance spécifique dépend également fortement du type de fibre (le papier kraft vierge à fibres longues issues de résineux est plus résistant que le papier kraft recyclé à fibres courtes pour un même grammage), de l’orientation des fibres (la résistance à la traction dans le sens machine est généralement 3 à 5 fois supérieure à celle dans le sens transversal pour un même grammage) et du procédé de fabrication (le papier kraft extensible est raffiné pour augmenter l’allongement au détriment d’une partie de la résistance à la traction). Précisez toujours les propriétés de résistance en même temps que le grammage, plutôt que d’utiliser ce dernier comme indicateur de résistance.

Quel est le grammage minimum des papiers Kangchuang ?

Kangchuang Papers produit du papier kraft industriel allant de 35 g/m² (qualités fines pour intercalaires et papier de protection) à 150 g/m² (qualités résistantes pour emballages et sacs). Des qualités fines spécialisées (inférieures à 40 g/m²) sont disponibles sur mesure, avec un volume minimum de commande de 3 tonnes. Les qualités standard en stock commencent à 40 g/m². Des grammages personnalisés compris entre 35 et 150 g/m² peuvent être produits sur mesure avec un minimum de 3 tonnes par point de grammage, ce qui permet aux transformateurs de choisir une qualité optimale plutôt que d'adapter une qualité standard à leur application.