Paperboard Weight & Thickness: GSM, Points and Caliper Explained

“How thick should my box be?” comes down to two measures – weight and caliper – that often confuse first-time buyers. Getting it right means a box that feels sturdy without paying for material you do not need. This article is part of our packaging materials guide.

GSM: weight

GSM (grams per square meter) measures how heavy the board is for its area. Higher GSM generally means a heavier, sturdier stock. It is the most common way paper and lighter board are specified – light wrapping stock is low GSM; a sturdy carton is higher.

Points and caliper: thickness

Caliper measures actual thickness, often in points (1 point = 1/1000 inch). A 24pt board is 0.024″ thick. Thickness drives how rigid and protective the box feels – two boards can share a GSM but differ in caliper depending on density.

How to choose the right thickness

• Light retail products – a thinner folding-carton caliper keeps cost down.
• Heavier or premium products – a thicker board feels substantial and protects better.
• Shipping – step up to corrugated rather than just thickening paperboard.

The trick is matching sturdiness to the product – over-thick board wastes money, too-thin board feels cheap and crushes.

We will recommend the weight

Not sure which to pick? Tell us your product and we will spec the right stock and caliper, with a free dieline. Start with our materials guide, then request your free quote or contact our team.