Maybe it’s just been the “apple barrel” cheap brand, but it seems that the lighter green varieties turn into a completely thin green liquid after a few years that smells vaguely like an alcohol/“chemical-ly.”
It’s specifically the greens that do this, so I’m wondering if there’s something in the green pigment that reacts with the binder after time. Most other cheap acrylics tend to dry out - reds more so. Is there some sort of slow chemical reaction happening with the greens instead?
Edit: I found a bottle of Orange just now that went off in the same way. Apple Barrel, matte, “Pumpkin Orange” 2047E.
It’s just a very striking way for paint to degrade. Drying out or just have the binder separate I get, but this one has to be involving some sort of fun chemistry.


second option still stays. it is posible that green pigment when it degrates releases something much less viscous and foul smelling (my guess is ammonia, as amines are very common in dyes).
Sorry i did not get what you were saying the first time. lack of sleep does not help either.