shows curves typical of a brittle plastic, high modulus, high yield strength, and low elongation. The challenge with this tensile behaviour is correctly identifying the linear region used to fit the modulus. The automatic peak fitting algorithm developed by was used to systematically analyse the curves, a breakdown of which is shown in Figure ). This algorithm works to iteratively minimise the coefficient of variation for a linear regression across a section of the stress-strain curve, as described in ASTM D638 standards. Two material dependent values are used; the initial (𝑗 = 1) maximum stress factor 𝜂 𝑗 = 0.9, and the stress ratio tolerance 𝑟 max = 0.3, found using trialand-error. The yield strength (𝑆 YS ) is calculated by constructing a line with the same gradient as the modulus fit, and a 0.002 mm/mm x-intercept offset, then finding the data intercept. The algorithm iterates by decreasing the value of 𝜂 𝑗 until the condition: