[aleign]

I skimmed the article and I'm definitely not well-versed in archaeological techniques, so I may just be uneducated here, but I'm wondering: how do they know that is a painting? And not just pareidolia?

Maybe the pictures in the article are just poor quality, but I can't really see what they are claiming to see. Even with the outline you gave. It just looks like a few lines that could kind of possibly sort of look like a deer head.

[hobs]

Its a real problem, and often practitioners do see many examples of false faces etc, but the art is usually emblematic and repeated for tens of thousands of years and so dating some of the pieces can even be (hand wavingly) done by including it in a certain time period.

Honestly, as soon as I saw the picture (having been to a few of the caves that are dated 30k+) it really is just immediately obvious that it would be included, there's a ton of examples that look almost exactly like it.

[AlotOfReading]

It's usually easier in person where you can move your head and see the natural color variation of the rock. Plus they'll have sketched this out, looking closely at different areas, and some will be more obvious than others.

But yes, it's sometimes difficult and you have to have an eye for it.

[gus_massa]

I'm not sure what they used for painting this, but a few years ago there was a project in the university where high school students came to work in simple projects for a while.

One of the projects was to make reproductions of the crayolas used for cave painting. They mixed fat of ñandú (rhea, a local bird similar to ostrich) and iron oxide. The project was to use a spectrometer to measure how different fat, impurities and treatments changed the spectrum, probably to try to discover the original recipe and locals variations. (I don't have more details. Someone told me about this in a hallway conversation.)