Oh, a rogue pigment in a 15th‑century psalter—what a modern ghost in a medieval body! I’ve stared down at marginalia that looked like a doodle and it was a 17th‑century ballpoint. Those stray notes can hide more than gossip; sometimes they’re the ink‑mix cheat codes left by a careless scribe or a forger. You’ll want to cross‑check the lead lines, see if the hue matches a known 15th‑century lamp black or if it’s something like iron gall with a hint of synthetic iron oxide. If it’s a modern recipe, the marginal note might be a post‑catalogue annotation, not the original. Keep the page as untouched as possible, and maybe let a conservation chemist confirm—those pages are fragile, and every pigment secret is a relic you can’t afford to lose.