Most shipping boxes are made from corrugated cardboard, a material built from fluted paper sandwiched between flat linerboard sheets. This construction gives corrugated boxes their signature combination of light weight, strength, and cushioning ability, making them the standard choice across e-commerce and general shipping.
Understanding Corrugated Cardboard Structure
Corrugated cardboard consists of three layers: an outer liner, an inner liner, and a wavy (fluted) medium sandwiched between them. This fluted middle layer is what gives corrugated cardboard its strength-to-weight advantage over flat cardboard — the arched flute shape resists crushing forces far better than a single flat sheet of the same material weight would.
Common Flute Types
- Single wall — one fluted layer between two liners; the most common configuration for standard shipping boxes
- Double wall — two fluted layers, used for heavier or more fragile items requiring extra protection
- Triple wall — three fluted layers, reserved for very heavy-duty industrial or large-item shipping
Flute size also varies (commonly labeled A, B, C, E, F flute, from larger to smaller flutes), affecting cushioning versus printability — larger flutes offer more cushioning, while smaller/micro flutes provide a smoother surface better suited to detailed printing.
Corrugated vs. Standard Cardboard (Chipboard)
It’s worth distinguishing corrugated cardboard from plain cardboard/chipboard, which is a single, flat, uncorrugated material — thinner, less structurally strong, and generally used for lighter-duty applications like cereal boxes or product packaging inserts rather than shipping.
Other Materials Used for Shipping
- Kraft paper mailers/bags — lightweight, used for soft or lightweight products like apparel
- Poly mailers — plastic or increasingly recycled/biodegradable film mailers, common for clothing and lightweight items where box rigidity isn’t necessary
- Molded pulp — an increasingly popular eco-friendly option, made from recycled paper fiber, often used for protective inserts within a box
Why Corrugated Dominates Shipping
- Strength-to-weight ratio — provides solid protection without adding excessive shipping weight
- Cost-effectiveness — widely manufactured and relatively inexpensive at scale
- Recyclability — corrugated cardboard is broadly recyclable, an increasingly important factor for environmentally conscious brands
- Printability — takes custom branding and printing well, especially on the outer liner
The Bottom Line
Corrugated cardboard is the standard, go-to material for shipping boxes due to its reliable balance of protection, cost, and recyclability. The specific flute type and wall configuration can be adjusted based on how fragile or heavy your products are, giving businesses meaningful flexibility within the broader corrugated category to match packaging to their specific shipping needs.
