I'm a composer, and for well over 30 years I used a trusty Sheaffer to write music on a near-vertical surface (essentially a huge board that sits on the music rest of my upright piano). When the pen finally gave up the ghost I bought a Lamy calligraphy pen, but within a second or two of my starting to write with it on the stand the ink stops flowing. It certainly never did that with the Sheaffer, which, incidentally, had a standard (and, as far as I can tell, fixed) nib.
I'm very glad to have come across these forums. Some posts touch on the subject, but my knowledge of fountain pens extends only to how to fill them with ink and write with them. So I'd be most grateful if somebody could point me in the right direction regarding a pen/nib that would meet my requirements: as I have discovered, some pens can cope with being held virtually horizontally and others can't, which puzzles me.
Thanks in advance for any guidance.