In the summer of 1905, Klee started using a new medium: blackened sheets of glass, which he worked on with a needle. Using the resistance of this unusual medium, he discovered a new form of artistic expression - the scratched drawing. In his diary, he described his discovery thus: »The medium is no longer the black line, it is the white. The light energy on a midnight background fits very well with the expression "let there be light". And so I glide gently over into the new world of tonalities.«