Paper & Board Grades · The Complete Guide

A paper or board grade is a classification that describes its raw material composition, manufacturing process, and structural design. Two boards with the same GSM can belong to completely different grades, and behave entirely differently in printing, finishing, and end use. Grade determines stiffness, surface quality, food safety suitability, recyclability, printability, and cost.

Understanding grades is essential for packaging specification. When a packaging buyer specifies "300 GSM board" without naming the grade, they have left the most important decision, the one that determines whether the carton will print well, erect correctly, survive the supply chain, and comply with food regulations, to whoever supplies the cheapest option. In India, this commonly results in specification drift from SBS to FBB to duplex across reprints of the same design, with each substitution visible in the quality of the finished carton.

Most packaging board is a multi-ply structure, several layers of different materials laminated together during manufacture. Each ply contributes different properties. The outer print surface ply determines printability and whiteness. The middle ply or plies determine stiffness, bulk, and cost. The back ply determines the reverse surface appearance and whether the board is food-safe.

Why ply structure determines performance

The outer print surface ply is the most important for printability and appearance, it must be smooth, bright, and receptive to ink and coating. The middle ply is the most important for stiffness and bulk, its fibre type and density determine how much the board resists bending. The back ply determines reverse surface quality and, critically, food safety, recycled grey back board contains contaminants that can migrate to food.

SBS (Solid Bleached Sulphate) is the premium packaging board and the standard for pharmaceutical, food, cosmetics, and luxury packaging in India. Every ply is made from virgin bleached chemical (sulphate / kraft) pulp, the entire board cross-section is white. There is no mechanical or recycled content.

What makes SBS the premium choice

• Whiteness, all-virgin bleached pulp produces the highest brightness and whiteness of any board grade. Colours printed on SBS appear more saturated and accurate than on any other board type. ISO brightness typically 85–90%.
• Surface smoothness, the tight, uniform fibre structure takes coating evenly, producing the smoothest print surface of any multi-ply board. Fine screen work, photographic images, and premium spot colours all perform best on SBS.
• Food safety, no recycled content means no contamination from mineral oils, inks, or other substances in recovered paper. SBS is the required grade for primary food packaging and pharmaceutical cartons in India and globally.
• Embossing performance, the uniform chemical pulp structure deforms cleanly and holds emboss relief better than FBB or duplex at equivalent caliper
• Folding performance, creases cleanly without the cracking at fold lines that FBB mechanical pulp can show. The bleached chemical fibres are long and flexible.
• Lamination performance, the smooth, uniform surface provides excellent adhesion for both thermal and wet lamination. Low moisture variation reduces post-lamination curling.

SBS limitations

• More expensive than FBB and significantly more expensive than duplex, the all-virgin fibre content commands a premium
• Lower bulk than FBB at the same weight, FBB achieves higher caliper at equal GSM due to the bulkier mechanical pulp middle. A 300 GSM FBB will be thicker than a 300 GSM SBS, which means the FBB carton feels sturdier despite being the same weight.
• Available in single-side coated (C1S) and double-side coated (C2S) variants, C1S is standard for cartons where only one side is printed. C2S for cartons with printed reverse panels.

FBB (Folding Box Board) is the most widely used packaging board globally for FMCG cartons. It is a three-ply or five-ply structure: a bleached chemical pulp top surface ply, a mechanical (groundwood or thermomechanical) pulp middle ply for bulk and stiffness at low cost, and a bleached chemical pulp back ply. Both the top and back surfaces are white, the mechanical pulp middle is the cream or yellow-toned core.

What makes FBB the volume standard

• High bulk at lower cost, the mechanical pulp middle achieves more caliper per gram than chemical pulp. FBB typically has 15–25% higher caliper than SBS at the same GSM, which means the carton feels stiffer at the same weight specification.
• Good print quality, the bleached chemical top ply provides a print surface nearly comparable to SBS. Process colour and spot colour printing on FBB is excellent for most commercial applications.
• Food safety, the top and back plies are virgin bleached pulp. The mechanical middle does not contact food in a normal carton construction. FBB is acceptable for food-adjacent packaging in most markets, though the specific regulatory position must be verified with the mill certificate for each lot.
• Cost advantage, FBB typically costs 15–30% less than SBS at the same GSM, making it the standard choice for high-volume FMCG cartons where SBS premium is not justified

FBB limitations vs SBS

• Slightly lower whiteness and brightness than SBS, the mechanical pulp middle affects the overall brightness slightly even though it is not the print surface. ISO brightness typically 80–87% versus 85–92% for SBS.
• More prone to surface cracking at deep emboss, the mechanical pulp fibres are shorter and less flexible than chemical pulp. Deep emboss (above 0.8mm) on FBB shows more surface crazing than SBS at the same depth.
• Higher moisture sensitivity, mechanical pulp absorbs and releases moisture more readily than chemical pulp. FBB cartons show more dimensional change in high humidity than SBS. Relevant for Indian conditions.
• Not recommended for pharmaceutical primary packaging in India, pharma regulators typically require SBS for tablet cartons due to the stricter migration standards.

Duplex board is a two-ply structure: a white coated top ply and a grey recycled back ply. The grey back is made from recovered paper, typically mixed waste including newspaper, office paper, and other recycled sources. It is the most economical board grade for packaging and the most widely substituted board in India when cost pressure drives specification decisions.

What duplex offers

• Lowest cost of any coated packaging board, the recycled grey back is significantly cheaper than virgin pulp
• Adequate print quality on the coated white top, for standard CMYK printing without very fine screen work, duplex produces commercially acceptable results
• Widely available from Indian mills, large domestic production base keeps prices stable
• The grey back is visually unremarkable in secondary packaging or wherever the back of the carton is not seen by the consumer

Duplex limitations · what most buyers do not know

• Not food-safe, the recycled grey back contains mineral oils, printing inks, and other contaminants from the recovered paper. These can migrate through the board structure to food content. Duplex should never be used for primary food packaging or pharmaceutical cartons. This is the most critical and most frequently violated board specification decision in Indian packaging.
• Lower stiffness per GSM, the recycled fibre has shorter, weaker fibres than virgin pulp. Duplex at 300 GSM is less stiff than SBS or FBB at the same weight.
• Delamination under stress, the two-ply structure can separate under high emboss pressure or when exposed to moisture. Deep emboss on duplex causes delamination at the emboss edges.
• Higher moisture sensitivity, recycled fibre absorbs moisture more readily than virgin fibre. Duplex cartons stored in humid conditions (Mumbai monsoon warehouses) show more dimensional change and potential delamination than SBS or FBB.
• Variable quality, recycled content means more batch-to-batch variability in caliper, smoothness, and print quality than virgin fibre boards

Coated art paper is the standard substrate for commercial printing, brochures, catalogues, annual reports, magazines, and quality leaflets. It is a paper (below approximately 200–220 GSM) with a mineral coating on one or both sides that provides a smooth, uniform surface for high-quality ink transfer.

The coating and what it does

The coating is a mixture of mineral pigments (typically kaolin clay and calcium carbonate), a binder (starch or latex), and optical brightening agents. It fills the surface micro-roughness of the paper fibres, producing a smooth, level surface with high ink holdout, the ink sits on the surface rather than absorbing into the fibres, giving sharper dots, higher density, and better colour gamut than uncoated paper.

Gloss, matte, silk, and satin variants

Uncoated paper has no mineral coating layer, the print surface is the paper fibre itself, with varying degrees of calendering (surface smoothing) but no applied coating. Ink absorbs into the uncoated surface rather than sitting on it, producing a softer, less saturated colour reproduction but a natural, tactile feel that coated paper cannot replicate.

Uncoated offset paper

• The standard for letterheads, forms, stationery, book interiors, and documents intended for writing or annotation
• Can be written on reliably with all writing instruments, ballpoint, rollerball, fountain pen, pencil
• More absorbent than coated paper, ink penetrates the fibres, producing lower density and a softer dot than the same ink on coated stock. Dot gain is higher on uncoated than coated paper.
• Better for inkjet overprinting (variable data, addressing, serialisation) than coated paper
• More expensive recycling path than some coated papers, but generally considered more environmentally friendly as the coating is not present to inhibit fibre separation

Premium uncoated · laid, wove, and textured papers

• Laid paper, has a pattern of fine parallel lines visible when held to light. Produced on a laid wire mould. The traditional choice for formal correspondence, legal documents, and prestige stationery. Connaught and other Indian brands are common.
• Wove paper, no visible wire pattern, the most common uncoated paper construction. Smooth, uniform surface.
• Textured uncoated, linen, felt, hammered, and other surface textures created by embossing rollers or special forming processes. Used for premium business cards, invitations, and stationery where the tactile texture is part of the design.
• Natural and recycled uncoated, cream, natural white, or off-white uncoated papers with visible recycled fibre content. Used for environmental brand communication and heritage brand positioning.