closeup of a hand using a dial caliper to measure the thickness of a beer carton

GSM vs. Point: Understanding International Paper Weights

Choosing the right paperweight impacts on the overall printability, strength, and stability of your package. So how do you choose the right paper weight for your project? 

Measuring paper weight is determined by the material’s thickness or gauge using a caliper. Calipers are inexpensive and come come in dial, sliding, or digital options. 



Now here's where it gets confusing...

While the rest of the world is happily using the metric system, the United States is holding on strong to the use of the British Imperial System for weights and measures

While we thankfully no longer measure things in units of barleycorn (yes, really, its equal to 1/3rd of an inch), the United States still uses measurements like inch, foot, yard, etc. 

Your caliper may read in point (1/1000th of an inch), GSM (grams per square meter), or both.

The Point System (pt)

  • Utilized in the United States
  • A point equals .001”, which means that 20-point board would be 0.02” thick
  • The higher the PT, the thicker the material
  • Measurements are only for thickness and do not take into consideration the stock weight of the material

Grams per Square Meter (GSM)

  • Commonly utilized in China and globally
  • Uses centimeters and meters for its key measurement
  • The higher the GSM, the thicker the material
  • Measurements consider weight, length, and breadth of the material rather than just the thickness

Material Matters!

Because GSM measurements are a ratio of thickness and weight, you cannot use point and GSM interchangeably. A 18-point coated 2 side (C2S) will weigh more than 18-point brown Kraft paper.

Conversion At-A-Glance

To help our customers quickly compare paperboard conversions, PAX Solutions created the paperboard conversion chart below. This chart lists the conversion for coated 1-sided board in point, millimeters, and gsm. To view conversion charts for coated 2-sided and greyboard, please visit our Packaging Resources page.

paperboard conversion chart; gsm vs. point

Still have questions about the right paperweight for your project? Contact PAX Solutions.