A biodegradable polyester mixture comprising: i) 71 to 91 wt%, based on the total weight of components i and ii, of a polyester I constructed from: a-1) 40 to 70 mol%, based on components a and b, of an aliphatic C 9 -C 18 dicarboxylic acid or of a C 9 -C 18 dicarboxylic acid derivative; b-1) 30 to 60 mol%, based on components a and b, of terephthalic acid or of a terephthalic acid derivative; c-1) 98 to 100 mol%, based on components a and b, of a C 3 -C 6 diol; d-1) 0 to 2 wt%, based on the total weight of components a to e, of an at least trihydric alcohol; e-1) 0 to 2 wt%, based on the total weight of components a to e, of a chain extender, and ii) 9 to 29 wt%, based on the total weight of components i and ii, of a polyester II constructed from: a-2) 40 to 70 mol%, based on components a and b, of an aliphatic C 4 -C 6 dicarboxylic acid or of a C 4 -C 6 dicarboxylic acid derivative; b-2) 30 to 60 mol%, based on components a and b, of terephthalic acid or of a terephthalic acid derivative; c-2) 98 to 100 mol%, based on components a and b, of a C 3 -C 6 diol; d-2) 0 to 2 wt%, based on the total weight of the components to e, of an at least trihydric alcohol; e-2) 0 to 2 wt%, based on the total weight of components a to e, of a chain extender. i) 71 to 91 wt%, based on the total weight of components i and ii, of a polyester I constructed from: a-1) 40 to 70 mol%, based on components a and b, of an aliphatic C 9 -C 18 dicarboxylic acid or of a C 9 -C 18 dicarboxylic acid derivative; b-1) 30 to 60 mol%, based on components a and b, of terephthalic acid or of a terephthalic acid derivative; c-1) 98 to 100 mol%, based on components a and b, of a C 3 -C 6 diol; d-1) 0 to 2 wt%, based on the total weight of components a to e, of an at least trihydric alcohol; e-1) 0 to 2 wt%, based on the total weight of components a to e, of a chain extender, and a-1) 40 to 70 mol%, based on components a and b, of an aliphatic C 9 -C 18 dicarboxylic acid or of a C 9 -C 18 dicarboxylic acid derivative; b-1) 30 to 60 mol%, based on components a and b, of terephthalic acid or of a terephthalic acid derivative; c-1) 98 to 100 mol%, based on components a and b, of a C 3 -C 6 diol; d-1) 0 to 2 wt%, based on the total weight of components a to e, of an at least trihydric alcohol; e-1) 0 to 2 wt%, based on the total weight of components a to e, of a chain extender, and ii) 9 to 29 wt%, based on the total weight of components i and ii, of a polyester II constructed from: a-2) 40 to 70 mol%, based on components a and b, of an aliphatic C 4 -C 6 dicarboxylic acid or of a C 4 -C 6 dicarboxylic acid derivative; b-2) 30 to 60 mol%, based on components a and b, of terephthalic acid or of a terephthalic acid derivative; c-2) 98 to 100 mol%, based on components a and b, of a C 3 -C 6 diol; d-2) 0 to 2 wt%, based on the total weight of the components to e, of an at least trihydric alcohol; e-2) 0 to 2 wt%, based on the total weight of components a to e, of a chain extender. a-2) 40 to 70 mol%, based on components a and b, of an aliphatic C 4 -C 6 dicarboxylic acid or of a C 4 -C 6 dicarboxylic acid derivative; b-2) 30 to 60 mol%, based on components a and b, of terephthalic acid or of a terephthalic acid derivative; c-2) 98 to 100 mol%, based on components a and b, of a C 3 -C 6 diol; d-2) 0 to 2 wt%, based on the total weight of the components to e, of an at least trihydric alcohol; e-2) 0 to 2 wt%, based on the total weight of components a to e, of a chain extender.