A new test for measuring leaf fracture toughness by cutting with a single inclined razor blade is described here, this having been developed to overcome some of the inadequacies of conventional double-bladed cutting tests, such as scissoring and shearing. The accuracy and precision of this test were determined by measuring the fracture toughness of various leaf types and homogeneous films, and comparing the results with those obtained by scissoring. The new test was found to display a low friction of cutting with great precision in measurements. Fracture toughness measurements of the specimens were considerably lower for the new test than those obtained by scissoring, owing to greater blade sharpness and reduced damage to the specimens during cutting. Despite this, the rankings of fracture toughness measurements for the specimens are similar for both the new test and scissoring, thus demonstrating the test's consistency with scissoring. The new test was found to be successful in measuring the fracture toughness of leaf blades and other thin, film-like materials. It was also able to overcome some of the difficulties of conventional double-bladed cutting tests, especially the estimation of energy expenditure that is extraneous to the work of cutting.