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Cushioning Selection Chart

How to match cushioning and void fill materials to product fragility and weight, and the difference between filling space and actually absorbing shock.

Ref PK-0208ASTM D1596

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

What it is

Packaging protection does three jobs. Void fill keeps the product from moving inside the box. Cushioning absorbs shock when the box is dropped or hit. Blocking and bracing holds heavy items in place. Many materials do only one of these jobs well. Fragility is how much shock a product can take before it breaks, often stated as a G-level. ASTM D1596 is the test method for the shock-absorbing characteristics of cushioning, which produces the cushion curves used to size cushioning.

How to use it

Decide how fragile the product is: robust, moderate, or fragile.
Decide the product weight and how much bearing area it has on the cushion.
Decide the job: void fill, surface protection, cushioning, or blocking.
Pick a material from the chart.
For fragile or high-value items, size the cushion from the supplier's cushion curves and confirm with a drop test.

Material comparison

Material	Main job	Best fit	Limits
Kraft paper void fill	Void fill, light blocking	Robust items; e-commerce	Little true cushioning
Air pillows	Void fill	Light, robust items	Can pop; little shock protection
Loose fill (peanuts)	Void fill	Irregular shapes, light items	Products migrate to the bottom over time
Bubble wrap	Surface protection, light cushioning	Light to moderate fragility, small items	Bubbles lose air under heavy loads
Polyethylene foam (sheet, plank)	Cushioning, blocking	Moderate to fragile items; repeated impacts	Must be sized to load and drop height
Polyurethane foam	Cushioning	Light, fragile items such as instruments	Not for heavy loads; can break down over time
Expanded polystyrene (EPS) molded	Cushioning, blocking	Electronics, appliances; single impacts	Poor at repeated impacts; can crack
Foam-in-place	Custom cushioning	Odd shapes, low volume, high value	Equipment and chemical handling required
Molded pulp	Blocking, light cushioning	Electronics, bottles, consumer goods	Limited for heavy shocks
Corrugated inserts and dividers	Blocking, separation	Bottles, multipacks, parts	Limited shock absorption

Key points

Too little cushion lets the product bottom out. Too much cushion under a light product makes the foam too stiff to work. The load per square inch must match the cushion.
Leave enough cushion thickness on every side, including the corners.
Double boxing with cushion between the boxes protects fragile items well.
Test with a drop or shipping test that matches how the box will travel.

Common mistakes

Treating air pillows or loose fill as cushioning for fragile items.
Using the same foam thickness for a light item and a heavy one.
Letting the product touch the box wall.
Skipping a drop test on a new pack design.

Governing standards: ASTM D1596 (dynamic shock cushioning characteristics); supplier cushion curves; shipping test methods such as ISTA procedures where required.

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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