Why Colors You See in an Art Museum Can’t Be Replicated Today

[mopinko]

4. an old bbc show called connections

was one of my kids favorite history shows, back in the day. seriously interesting look at the history of inventions, mostly. but really looking at what led to innovations, which sometimes are presented as just popping up. but he really looked at all the crazy things that sometimes lead to innovation.
one i remember in particular was about ink. the basic story was that when they first started using gas for lighting, and manufacturing, they were just using gas vented from coal mines. this "town gas" was very contaminated. when they burning it they got lots of residue. in an effort to keep the enterprise profitable, they started looking at these residues.
and from there the whole german chemical industries of the early 19th century were born.
turns out there were tons of colorants in that gas.

learned about a lot of this color chemistry because potters have to know that stuff. same chemicals in ink and paint these days.