Simon Berger is an artist who works with a hammer and glass. He has figured out a way to crack the glass so precisely that it creates an image of a face. It’s a delicate process that has taken him three years of trial and error to get right. Sometimes it takes him one try, but other times it can take him five. And an expensive series of mishaps could cost hundreds of Swiss francs. One wrong hit, and he’ll have to start all over again.