Here are two historically important collages by Jean (Hans) Arp. “Collage with Squares Arranged According to the Laws of Chance” which is in the collection of the Museum of Modern Art and “Untitled (Forest)”, a painted wood relief, which is in the collection of the National Gallery of Art. Both are from 1916-17.
The MoMA page concerning Collage with Squares Arranged According to the Laws of Chance presents excerpts from various publications including this gallery label text from the 2006 Dada show:
Accounts by several Dadaists describe how Arp made “chance collages” such as this one: by tearing paper into pieces, dropping them onto a larger sheet, and pasting each scrap wherever it happened to fall. The relatively ordered appearance of Arp’s collages suggests, however, that the artist did not fully relinquish artistic control. Skeptical of reason in the wake of World War I, Arp and other Dadaists turned to chance as an antidote.