Representative stress-strain curves of gels formed by mussel-mimetic processing involving initial cross-linking at pH 3 and then equilibration to the pH values indicated. Samples were deformed in multiple compression cycles, where the strain was successively increased to 10 % (black), 20 % (red), 40 % (blue), 60 % (purple), 70 % (green), and 80 % (yellow). In the case of materials equilibrated at pH 7, the final two loops were unnecessary due to failure at ~55 % strain. Insets show detail in the low strain regime (0-50%).