I spend quite a bit of time reading the forums over on the Fountain Pen Network and I often see questions about the differences between the papers used in the various Clairefontaine (Rhodia, Clairefontaine, Quo Vadis) writing paper products.
I would first like to note that I am specifically referring to the selection of Clairefontaine products that Exaclair imports into the US, (or are manufactured in the US for the US market.)
Most Clairefontaine branded products (Spiralbound, Staplebound, Clothbound & Hardcover) contain what I would refer to as their “typical” bright white 90g paper. Though the Clairefontaine Triomphe writing pads also contain 90g bright white paper, it’s surface texture is somewhat smoother and more glass-like than the “typical” 90g paper.
Most Rhodia branded products (Staplebound & Wirebound) contain what I would refer to as their “typical” bright white 80g paper. The main exception would be the off-white 90g paper used in the US manufactured Webnotebook. (Note: The rest of the world will also soon have access to the 90g Webbie.)
The US made Quo Vadis Habana journals contain a 64g Clairefontaine paper in the small version, and the “typical” 90g in the larger version. These same papers are also used in the Rhodia Planners- 64g in the small version and 90g in the large. (Note: The new small blank Habanas will contain 90g paper.)
Having had the opportunity to try all of the above options, my personal preferences tend to lean towards the 80g Rhodia paper and the 64g in the Habana. (At least until the blank Webbies arrive.) While this might be a less than scientific way of describing my experiences with these products, I find the 90g Clairefontaine to have a bit of “drag” and the 80g Rhodia to be “faster.” I write super fast (and often sloppy) and I am always looking for a paper which can send my pen nibs flying at 100mph. The Clairefontaine Triomphe which is also 90g, is one of the “fastest” writing surfaces I’ve yet to encounter.
The 90g off-white paper in the Webbie is a fast smooth paper like the Triomphe, though maybe just a tad less so.
Using a fountain pen on any of the above papers? Each of these papers are super smooth, and be sure to take notice that the pen nibs will write true to their nib width as there isn’t any of the “spreading” that can happen with other kinds of papers. The 80 & 90g papers are fairly impervious to ink bleedthrough, but some have reported seeing inks push through on the 64g.
Quo Vadis planners use a variety of different paper weights that I have not tested – a handy chart on which paper is found in each planner can be found here. Exaclair claims the papers used in the Quo Vadis planners to be fountain pen friendly at 85g and above. (And yes, technically, the Rhodia planner is made by Quo Vadis but it is a Rhodia product.)