Hi Fellow Pen Appreciators I have recently bought a bottle of Diamine Royal blue and when I opened it I notices spots or patches of oily something floating on top of the ink. It makes up a shiny reflective and very slightly rainbow-y layer. The ink itself is rather dark and the thing on the surface really reminds me of spilled oil on the seas. Is it a precursor or a warning of the feared SITB? Or is it normal I just never met it before? (I'm a newbie to bottled inks and pretty new to fountian pens as well...) Since then I've seen something a bit similar to that in my Diamine Asa blue, but I thought I'll take the careful option and ask before I put it into more precious pens and even more pronouncedly to sargasso Sea. Thank you very much for your opinion or advice