Well, I ain't no expert on fountain pens. But, I do know a thing or two about paper. So, let's examine a few terms: "Cotton" paper will have a "rag content" from 25% up. In MOST cases, it will also have a broad "tooth". "Tooth" is the size of the weave of the sheet, if you look at "fine cotton" paper, you will usually be able to see "ups and downs" or peaks and valleys. Seems to me this is the MOST important consideration as you look for paper. A fountain pen ink will not leave a nice crisp line on "toothy" paper - I don't believe. You are looking for a smooth writing surface, that would be more typical of "ink-jet" sheets. In fact, the ink-jet paper is also designed to accommodate "drying" - or minimize smearing in the fountain pen arena.
So, be careful what you call "Quality" paper. Talk with Anthony or Lou and see what characteristics THEY consider important. Not to "Knock" Chasper, his idea is correct, I suspect HE knows what he means. But, as I read it, I find it could easily lead you to the wrong "paper counter".
No offense meant, Gerry.
FWIW