Geiger’s Zehn erotische Aquarelle (Ten Erotic Watercolours) are considered to be among the most beautiful and rarest of German erotic portfolio works. The erotic art historian Hayn-Gotendorf explains that Geiger did not release these during his lifetime because they would ‘collide with good morals’, but ‘in his estate were found a number of ultra-realistic drawings and watercolours, which although venturing into reckless eroticism yet had high artistic value’.

The 1909 edition includes an introduction and appreciation by A. Normann.

Zehn erotische Aquarelle was published by Gesellschaft Österreichischer Bibliophilen in a limited edition of 530 numbered copies.