When all of these regulations on what you can carry on Airlines began to come in where I live - mostly (UK), I rang my local airport to seek clarification on carrying paints on aircraft ( I use the Humbrol small tins). They advised me that as the contents consisted of flammable liquid material, they would NOT be allowed to be packed in either carry-on baggage - NOR should they be packed in main baggage.
So.........I don't do that on airplanes - though oddly, ferries to and from the Continent of Europe don't seem to mind!
I have never been too inconvenienced though, as most places I have been to, either have a hobby shop either nearby - or one that has been prepared to post me what I want (Humbrol paint in tins) - at very similar prices to that found in the UK.
Now HOW the small tins of paint get to wherever you are in the World - is another question???? I can't believe they get there without an airplane being involved somehow...............but................there you go!!! You can't do it yourself apparently.
jb