kartonit

Cardboard, or kartonit in Finnish, refers to a family of paper-based packaging materials produced from wood pulp and recycled fibers. The term encompasses corrugated cardboard, which has a fluted middle layer between linerboards, and solid cartonboard (also called paperboard), used for rigid boxes and folding cartons. Corrugated cardboard is valued for its combination of strength, lightness, and cushioning, and comes in single-wall, double-wall, and triple-wall constructions depending on the number of linerboards and flute layers. Flute types include A, B, C, and E, which influence thickness and crush resistance. Solid cartonboard is thicker and more rigid, suitable for consumer packaging and display products.

Production generally starts from cellulose fibers derived from wood or recycled paper. The pulp is refined, formed into sheets, and further processed: corrugated boards receive a fluted medium bonded to linerboards; folding cartons may be coated or printed and cut into shapes. Adhesives are typically starch- or synthetic-based.

Common uses include shipping containers, retail packaging, food and beverage packaging, and point-of-sale displays. Cardboard packaging is usually designed for lightweight yet protective performance and is often printable, allowing branding and product information to be displayed.

Cardboard is widely recycled; used boxes are collected, repulped, cleaned, and turned into new containerboard or paper products. Recyclability varies with coatings and laminates. Sustainable forestry and responsible sourcing (e.g., FSC certification) are important aspects of the industry, which also seeks to reduce energy and water use in production and to promote reuse and composting where feasible.