Materials
Grammage (gsm)
Grammage is the mass of a sheet material per unit area, normally stated in grams per square metre (g/m² or gsm).
What it means in packaging
It helps specify and compare stock, but does not directly state thickness, stiffness or compression strength. Fibre furnish, layering and coatings can change how two stocks with identical grammage behave.
A practical example
A 350 gsm carton board and a different 350 gsm board can need different crease settings and dimensional allowances.
What to check
Request caliper and relevant performance data alongside grammage when choosing a production material.