Jet Pens did an excellent post on their blog last month featuring the Best Notebooks for Fountain Pens. We were very proud that they recommended Rhodia notebooks in two categories!
Rhodia Webnotebooks were their top choice for notebooks with an elastic closure. Webbies come in lots of sizes and orientations (notebook, landscape, reporter style etc.).
They love the Rhodia pocket size notebook for a go-everywhere notebook. They noted it is the best for no showthrough, even with wet inks.