Glossary Category: Cardboard Materials and Structure
D
- Double-wall – Types of Cardboard
- A cardboard structure consisting of two overlapping flutes of different heights, separated by an intermediate liner and enclosed between two outer covers (a five-layer structure in total). The combination of different flute types (for example, a micro-E flute and a low B flute) offers excellent resistance to vertical compression along with a very flat outer surface, ideal for high-quality graphic printing. It is the recommended choice for heavy shipments, stacked warehouse loads, and fragile products.
K
- Kraftliner – cover stock
- A very high-quality paper produced primarily from coniferous wood sulfate pulp (long-fiber virgin cellulose). It is characterized by excellent mechanical properties, including exceptional tensile strength, tear resistance, burst strength, and crush resistance. It offers high dimensional stability and is particularly resistant to moisture and climatic variations. It is the optimal choice for packaging intended for international shipping, heavy goods, and high-performance protective e-commerce packaging.
M
- Medium (recycled fluting) – corrugating paper
- Corrugated medium made entirely from recycled waste paper fibers. It is the standard and most environmentally friendly material used to create the inner flute of corrugated cardboard. It offers good elasticity and shock absorption (cushioning) properties for light- to medium-weight goods handled under standard environmental conditions.
O
- Flute B (low flute) – types of cardboard
- Corrugated board with a thickness ranging from 2.5 to 3.2 mm. Characterized by excellent resistance to puncture and crushing, it also offers a surface suitable for sharp flexographic printing. It is widely used for medium-sized shipping boxes, gift boxes, and protective packaging in the wine industry.
- C-flute (medium flute) – types of cardboard
- Corrugated profile with a thickness ranging from 3.5 to 4.5 mm. It offers maximum shock absorption and excellent resistance to vertical compression. It is the industry standard for standard industrial storage, moving, logistics, and shipping cardboard boxes .
- E-flute (microwave) – types of cardboard
- Very low corrugation profile with a thickness ranging from 1.2 to 1.8 mm. Thanks to the high frequency of corrugations per linear meter, it offers an extremely flat, rigid, and crush-resistant surface. It sets the standard for high-definition offset and digital printing, making it ideal for commercial boxes, personalized gift boxes, cosmetics packaging, and luxury e-commerce products.
- Single-wall (plain) – types of cardboard
- A paper-based packaging structure consisting of a single sheet of corrugated paper sandwiched between two flat cover sheets (inner and outer liners). This configuration offers an extremely lightweight, versatile, and economical packaging solution. It is suitable for shipping non-fragile products, for commercial boxes, and for e-commerce shipments with low weights (generally up to 10 kg).
S
- Semi-chemical (semi-chemical fluting) – corrugating papers
- Paper for forming the inner flute, produced through a semi-chemical process that preserves the natural lignin of softwood fibers. This treatment gives the paper exceptional structural rigidity and high resistance to flat compression. It is essential for the production of packaging that must withstand heavy loads or is exposed to high humidity, such as packaging for the produce and wine industries intended for storage in cold storage facilities.
T
- Testliner – cover stock
- Cover stock composed primarily of selected recycled fibers, structured in multiple layers. The outer surface layer is often treated or laminated with a percentage of virgin cellulose to improve its appearance, color uniformity, and ink receptivity. Although its mechanical properties are slightly inferior to those of Kraftliner, it offers excellent value for money and is the ideal solution for standard shipping and eco-friendly protective packaging.
- Triple-wall – Types of Cardboard
- An extremely sturdy structure consisting of three overlapping flutes separated by intermediate liners (a total of seven layers). Developed for heavy-duty industrial applications, it offers performance comparable to that of wood or metal in terms of puncture and compression resistance. It is used for export packaging, ocean freight, and the transport of exceptionally heavy machinery or industrial components.