For all the hype around folding phones, there’s plenty of anxiety concerning how well those bendable screens survive long term. Depending on who you ask, they’re either weaker than spider silk or hardy enough to make your average lumberjack weep with envy. That’s why Sam Rutherford took matters into his own hands, spending the last year running his own durability test. He’s been using his Z Fold 4 without a case, leaving its factory-installed screen protector as the only defense.