Ancient South Africans probably used milk from wild animals as a paint base almost 50,000 years ago, according to a new study in the journal PLOS ONE.

Residue from a stone flake taken from the Sibudu Cave in South Africa shows that paint made of a mixture of milk and ochre (a clay earth pigment) existed as long as 49,000 years ago in the region. While ochre has been ground up to produce powdered paint for at least 250,000 years, this is the first evidence that South Africans mixed it with milk. Furthermore, the milk-based paint predates cattle domestication, meaning that people had to go out and kill lactating animals to get it.

Paint remnants found in South Africa. Villa et. all, PLOS ONE (2015)

An international team led by University of Colorado Museum curator Paolo Villa used chemical analysis to identify the presence of casein, a protein in milk, in the paint remnants. The milk was mixed together with the earth pigment to make paint that would decorate stone, wood, and people’s bodies.

Cattle domestication originated around 10,500 years ago in the Middle East and arrived in South Africa sometime between 1,000 and 2,000 years ago. The milk probably came from a wild relative of the cow, like a buffalo or a kudu. "[O]btaining milk by killing a lactating wild bovid and then mixing it with ochre shows that [people] experimented with coloring materials in creative ways," the study reads. Plus, having to hunt down the source of your body paint likely made it much more valuable.