The Paper Buyer's Glossary: 50+ Essential Terms Every Importer Should Know

The paper industry speaks its own language. When a supplier says "C2S art board with 92% brightness, PPI 600, caliper 12pt," they are communicating precise specifications — but only if you understand the vocabulary.

This glossary defines 50+ essential terms organized by category. Use it as a reference when reading specifications, comparing quotes, or communicating with suppliers.

Paper Grades & Types

Art Paper / C2S: Paper coated on both sides (Coated 2 Sides). Used for high-quality printing — magazines, catalogs, brochures. Available in gloss and matt finishes.

C1S: Coated one side. Used for labels and packaging where only the outside needs printing.

CKB (Coated Kraft Back): Board with a coated white printing surface on top and unbleached kraft fiber on the reverse. Used for beverage cartons and frozen food packaging.

Chipboard: Another term for grey board — dense recycled paperboard for structural applications.

Duplex Board: Paperboard with a coated white top layer and grey recycled back layer. Economical choice for printed cartons.

FBB (Folding Box Board): Virgin-fibre board with coated surfaces, engineered for clean folding and high-quality printing on carton converting lines.

Grey Board: Dense structural board made from recycled fiber. The standard material for rigid boxes and book covers.

Kraft Paper: Strong paper made from kraft (sulfate) pulp. Natural brown or bleached white. Used for bags, wrapping, and industrial packaging.

LWC (Lightweight Coated): Low-grammage coated paper (40–80 gsm) for magazines and catalogs where postal weight matters.

MG Paper (Machine Glazed): Paper with one glossy side (dried against a heated cylinder) and one matte side.

NCR Paper (No Carbon Required): Carbonless copy paper that transfers writing pressure to underlying sheets through micro-encapsulated dye.

Newsprint: Low-cost, uncoated paper for newspapers and mass-circulation printing.

Woodfree Paper: Paper made from chemical pulp with lignin removed. Higher brightness and better aging than mechanical (wood-containing) papers. Used for books, notebooks, and office paper.

Physical Properties

Basis Weight: Weight of paper per unit area. Expressed as GSM (grams per square meter) or lbs (pounds per ream in North America).

Bulk: The volume occupied by paper per unit weight. Measured in cm³/g. Higher bulk means thicker paper at the same GSM. Important for book publishers.

Caliper: Physical thickness of a single sheet. Measured in microns (µm), millimeters (mm), or points (pt).

Density: Weight per unit volume (g/cm³). The relationship between GSM and caliper. Higher density = thinner paper at the same GSM.

Formation: The uniformity of fiber distribution in a sheet. Good formation = even look-through, consistent strength. Poor formation = cloudy appearance, weak spots.

Grain Direction: The direction in which most fibers are aligned. Paper folds more easily parallel to the grain. Expands more across the grain with moisture changes.

GSM (Grams per Square Meter): The standard international unit for paper basis weight. Also written as g/m² or gsm.

Moisture Content: Percentage of water weight in paper relative to total weight. Typically 5–8% for most grades.

Opacity: The ability of paper to prevent show-through of printing from the reverse side. Higher opacity = less show-through.

Points (pt): North American thickness unit. 1 pt = 0.001 inches = 25.4 microns.

Porosity: The degree to which paper allows air to pass through. Affects ink absorption and drying.

Stiffness: Resistance to bending. Critical for carton board and packaging. Related to caliper, density, and fiber composition.

Whiteness / Brightness: Measurement of light reflectance. Higher values appear whiter/brighter. ISO brightness (diffuse blue reflectance) vs CIE whiteness (full spectrum).

Printing & Surface Properties

Coated Paper: Paper with a surface layer of mineral coating (clay, calcium carbonate) for improved print quality. Gloss, matt, silk, and satin finishes available.

Dot Gain: The increase in halftone dot size during printing. Affected by paper absorbency, ink, and press conditions.

Gloss: Specular reflection of light from a paper surface. Higher gloss = shinier, more reflective.

Ink Holdout: The ability of paper to keep ink on the surface rather than absorbing it. Better holdout = sharper images, less ink consumption.

Picking: The lifting of fibers or coating particles from the paper surface during printing. Caused by ink tack exceeding surface strength.

Runnability: The ability of paper to perform on a printing press or converting machine without breaks, jams, or quality issues.

Smoothness: Surface flatness of paper. Measured by air leak methods (Bendtsen, Sheffield). Smoother paper = better print quality.

Uncoated Paper: Paper without surface coating. Ink absorbs into the fiber. Natural, tactile appearance.

Converting & Finishing

Creasing: Creating a compressed line in paperboard to enable clean folding without cracking.

Die-Cutting: Cutting paper or board into shapes using a steel rule die.

Embossing: Creating a raised (embossed) or recessed (debossed) design on paper using pressure and heat.

Foil Stamping: Applying metallic or pigmented foil to paper using a heated die. Also called hot foil stamping or hot stamping.

Lamination: Bonding a plastic film (gloss, matt, soft-touch) to paper or board for protection and appearance.

Perforating: Creating a line of small holes to enable easy tearing.

Scoring: Creating a groove in heavy board to enable folding. Similar to creasing but for thicker materials.

Slitting: Cutting a master roll into narrower rolls of specified width.

Spot UV: Applying UV varnish to selected areas only, creating contrast between gloss and matt areas on the same surface.

Certifications & Testing

Burst Strength: Resistance to rupture under pressure. Measured in kPa. Important for packaging and bags.

Cobb Test: Measures water absorbency of paper. Grams of water absorbed per square meter in a specified time. Lower values = more water-resistant.

FSC (Forest Stewardship Council): International certification for responsibly managed forests and chain of custody. Labels: FSC 100%, FSC Mix, FSC Recycled.

KIT Test: Standard method (TAPPI T559) for measuring grease resistance. Scale of 1–12. Higher numbers = better grease resistance.

ISO 9001: Quality management system standard.

ISO 14001: Environmental management system standard.

SGS: Independent testing, inspection, and certification company.

TAPPI: Technical Association of the Pulp and Paper Industry. Publishes standard test methods.

Tear Strength: Force required to continue tearing paper from an initial cut. Measured in mN. Important for bags, wrapping, and industrial papers.

Tensile Strength: Force required to break a strip of paper under tension. Measured in kN/m. Important for web-fed printing and converting.

Logistics & Trade

B/L (Bill of Lading): Shipping document issued by the carrier. Serves as receipt for goods, contract of carriage, and document of title.

CIF (Cost, Insurance, Freight): Incoterm where the seller arranges and pays for ocean freight and insurance to the destination port.

Certificate of Origin: Document certifying the country where goods were manufactured. Required for customs clearance in many countries.

FCL (Full Container Load): A container exclusively used by one shipper. Opposite of LCL.

FOB (Free On Board): Incoterm where the seller delivers goods onto the vessel at the port of loading. The buyer arranges ocean freight.

LCL (Less than Container Load): Shared container space with other shippers. Higher per-unit cost than FCL.

MOQ (Minimum Order Quantity): The smallest quantity a supplier will accept for an order.

TEU (Twenty-foot Equivalent Unit): Standard unit for counting container capacity. 1 × 20ft container = 1 TEU. 1 × 40ft container = 2 TEU.

Quick Acronym Reference

The Bottom Line

You don't need to memorize every term. But when your supplier sends a specification sheet, you should understand what each value means and which ones matter for your application. Bookmark this page — it's your quick reference for clearer communication and better sourcing outcomes.

Have a term you'd like added? Let us know.

Related Products and Guides

• Paper Thickness Guide — GSM, caliper, points explained
• Materials Library — technical specs for all grades
• How to Source Paper from China — complete guide