How to read a TDS — and why 270 g is not 300 g

A technical data sheet (TDS) is the paper mill’s or board mill’s own description of a grade: grammage, thickness, stiffness, brightness, moisture and more, each with a nominal value and a tolerance. When a factory quotes “300 g board”, the TDS is what that promise means.

The lines that matter most

• Grammage (g/m²) — weight per square metre, with a tolerance, usually given as ± %.
• Thickness / caliper (µm) — affects how rigid the pack feels and how it runs on machines.
• Stiffness / bending resistance — decides whether a carton holds its shape on the shelf.
• Test methods — the ISO or TAPPI standard each value was measured with. Values from different methods cannot be compared.

Why 270 g versus 300 g matters

The difference is 10% of the fibre — and fibre is most of the cost. In the hand, the two are almost impossible to tell apart. On the shelf, the lighter carton may bow, crease badly or feel cheap. On a large order, 10% less fibre is a real saving for whoever quietly made the switch.

Check it yourself in two minutes

Cut a square of exactly 10 × 10 cm. That is 0.01 m². Weigh it on a scale accurate to 0.01 g and multiply by 100. A sample of 3.00 g means 300 g/m²; 2.70 g means 270 g/m². Weigh several samples and use the average.

How PACKbid uses the TDS

Every bid must include the TDS. At production start the factory photographs the reel label, and during the run it weighs samples from start, middle and end. If a value is outside the TDS tolerance, an issue opens and the payment stops.