Are your paintings on relays?
Or are hypertextual links on relays?

Anything which isn't part of the text note itself, and actually physically stored on relays, is not resilient.

Services like nostr.build, which you use, are simply classical web image host, not at all more resilient than any other image host like Imgur or the like, or even Instagram.
They are all centralized Web image hosting services. The fact that some of them happen to have "Nostr" in the name doesn't add any more resistance.

What paintings have you actually stored on relays? And how?
Because the latest relevant post I see from you contains nothing but mere *links* to paintings, while the painting themselves are on the centralized nostr.build platform.