Bio-based content is a percentage by weight. It records how much of the material originated in biomass. It says nothing about how the remainder was made, how the material performs, whether it biodegrades, or what happens to it at end of life.
Ask suppliers for the figure determined under EN 16785-1 or ASTM D6866, by weight, for the finished sheet rather than for one input layer. A supplier who quotes a figure for the coating alone has answered a different question.
From 27 September 2026 the ECGT Directive makes an unsubstantiated generic environmental claim unlawful in the EU. A bio-based claim without a number is exactly that.
