Packaging Reference Library · Technical Reference

Cushioning Materials Overview

Cushioning protects a product from shock and vibration in shipping. Bubble, foam, air pillows, paper and molded pulp each absorb energy differently, and the right one depends on product weight, fragility and drop height.

Ref PK-0119ASTM D1596

Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.

What it is

Cushioning sits between the product and the box wall. When the box is dropped, the cushion compresses and slows the product down so the force on it stays below what it can survive. Void fill only keeps the product from shifting; cushioning must actually absorb impact. Many shipments need both.

How to identify

Bubble cushioning: plastic film with trapped air bubbles, sold in rolls by bubble height.
Foam: polyethylene (firm, closed cell), polyurethane (soft, open cell), or foam-in-place. Sold as rolls, sheets, planks or fabricated inserts.
Air pillows and air cushions: film tubes inflated on a machine. Pillows are mostly void fill; quilted air cushions can wrap items.
Paper: crumpled or folded kraft from a dispenser, or coiled paper pads.
Molded pulp: formed recycled fiber shaped to the product, like egg cartons and electronics trays.

Cushioning materials compared

Material	Shock protection	Reuse after impact	Best for	Notes
Bubble	Good for light items	Fair, bubbles can pop	Wrapping small and medium items	Larger bubbles for heavier items
Polyethylene foam	Very good	Good, recovers	Repeated impacts, heavy or fragile items	Fabricated inserts for exact fit
Polyurethane foam	Good for light, delicate items	Good	Instruments, cases	Soft, can take a set under load
Foam-in-place	Very good, custom fit	Fair	Odd shapes, low volume	Needs dispensing system
Air cushions	Fair	Poor if punctured	Light items, blocking	Low weight, low storage space
Paper	Fair	Poor, crushes	Medium items, blocking and bracing	Curbside recyclable
Molded pulp	Good when designed to product	Poor	Repeat products in volume	Needs tooling

Key points

Cushion performance depends on how much load sits on each square inch of cushion (static loading) and the cushion thickness. Too little load and the cushion is too stiff; too much and it bottoms out.
Cushion curves from foam makers show the shock transmitted at different static loads and drop heights. They are produced by test methods such as ASTM D1596.
Thicker cushioning protects from higher drops but adds box size and freight cost.
Protect corners and edges, where boxes are most often dropped.
See the cushioning selection chart for quick picks by product type.

Common mistakes

Using void fill alone for a fragile product.
Packing a heavy item on a small foam pad that bottoms out.
Leaving no cushion between the product and the box bottom.
Choosing by material cost without counting damage and freight.

Governing standards: ASTM D1596 (dynamic shock cushioning characteristics); ISTA test procedures for package performance.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.

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