Corrugated board types are classified based on the flute profile (designated by letters) and the number of layers. The height and density of the fluting determine the wall thickness, weight, and intended use of a specific package.
Types of corrugated cardboard (by number of layers)
- Thin and special boards (Micro-flutes)
- F-flute (Micro-micro-flute):
- Board thickness: approx. 1.1 – 1.2 mm
- Flute height: approx. 0.75 mm
- Application: Very thin, an alternative to solid board; small retail boxes, packaging for luxury cosmetics or pharmaceuticals featuring high-quality offset printing.
- G-flute:
- Board thickness: approx. 1.2 – 1.4 mm
- Flute height: approx. 0.8 mm
- Application: Used in the food and cosmetics industries for very small, rigid unit packages.
- E-flute (Micro-flute):
- Board thickness: approx. 1.5 – 1.8 mm
- Flute height: approx. 1.1 – 1.6 mm
- Application: Extremely popular in e-commerce for attractive die-cut boxes for cosmetics, electronics, or jewelry. The dense flute arrangement creates a smooth surface ideal for printing.
- F-flute (Micro-micro-flute):
- Three-layer boards (Standard) These boards consist of two flat outer layers (liners) and a single fluted layer in the middle.
- B-flute:
- Board thickness: approx. 2.5 – 3.0 mm
- Flute height: approx. 2.1 – 2.9 mm
- Application: The “happy medium” in logistics and e-commerce. Used to manufacture versatile standard flap boxes and die-cut boxes for clothing, footwear, or books. It offers a good balance between rigidity and cushioning.
- C-flute:
- Board thickness: approx. 3.8 – 4.0 mm (sometimes up to 4.5 mm)
- Flute height: approx. 3.5 – 4.2 mm
- Application: The tallest of the common single-wall flutes. It offers excellent cushioning and high resistance to vertical compression. Used for heavier shipments (10–20 kg), ceramics, and bulk shipping cartons.
- A-flute:
- Board thickness: approx. 4.5 – 5.0 mm
- Flute height: approx. 4.0 – 4.8 mm
- Application: An older type of tall flute. Rarely used nowadays as a single layer because it is susceptible to side-impact damage; more commonly found in older types of transport packaging.
- B-flute:
- Five-layer cardboard (For heavy-duty applications) Made by combining two corrugated layers and three liners. It offers exceptional resistance to pressure and mechanical damage.
- EB-flute:
- Board thickness: approx. 4.0 – 5.2 mm
- Application: A combination of E-flute (outer layer, suitable for printing) and B-flute (inner layer). Used for heavier premium products, home appliances, and bulk packaging (FMCG).
- BC-flute:
- Board thickness: approx. 6.5 – 7.0 mm
- Application: A combination of B-flute and C-flute. Extremely rigid and thick board, ideal for transporting heavy goods (over 15–20 kg), large-sized items, and international palletized shipments.
- EB-flute:
- Seven-layer cardboard (Industrial)
- BCC-flute or K-flute (triple combinations):
- Board thickness: approx. 11.0 – 15.0 mm
- Application: The strongest corrugated board available. Used in heavy industry and the automotive sector, as well as for transporting machinery, where it effectively replaces traditional wooden crates.
- BCC-flute or K-flute (triple combinations):