The thing that bothers me about #cerulean paint is how determinedly it sticks to even silicone (this cup is one I used to soak fake moss in for one of my shadowbox projects here https://blog.outtolunch.me.uk/2022/12/21/i-made-my-second-shadowbox/).
And I have never been able to get that pigment off. It also stains my skin for longer than other colours. But when I use that paint on actual projects, the moment I use any kind of topcoat to seal it, whether diluted PVA or acrylic varnish, it will reactivate and start to smear.
I did some tests here:
https://blog.outtolunch.me.uk/2023/03/13/the-instability-of-cerulean-paint/
Any artists want to chime in? I have the same issue with cyan ink on photo paper. It's the only one that isn't stable. I've seen other artists be able to brush varnish over their projects with blues and cyans, even when they're using cheap Apple Barrel paints (which I'm assuming would be comparable quality to the cheap paints I use).
