Ancient Hunter-Gatherers had used natural materials to create paint and pigments for hundreds of thousands of years but until recently it was not known how they had actually made it. Now a team of scientists from the University of Missouri (USA) have been using 21st Century technology to try and re-create the processes used by our ancestors, all that time ago.
     A considerable amount of time and money has been spent in recent decades trying to produce a thermo-stable paint which would be suitable for use in the high tech world and demanding environment of aerospace engineering. The scientists analysed the ochre pigments which had been used in the Rock Art of British Columbia (Canada), which dates back to the Megalithic Era and is still vibrant and colourful today. What they found was astonishing.
     To produce a stable paint from  ochre our ancestors harvested aquatic iron-rich bacteria and then deliberately super heated it to between 750 and 850 degrees Centigrade, to produce the distinctive red paint.
     Brandi MacDonald, leader of the team, is quoted as saying "Ochre is one of the only types of material that people have continually used for over 200,000 years, if not longer. Therefore we have a deep history in the archaeological record of humans selecting and engaging with this material but few people study how it is actually made".

Edited from Nature and PhysOrg (19 Nov 2019)