Paper Subtlety
I recently made a 5×7” accordion fold journal with high quality watercolor paper (Arches, 140lb, CP) and started it off with continuing studies of nests and eggs. Wow—what a difference paper makes! I loved the subtle effects that can be achieved with this paper, especially for nest materials and delicate egg markings (the white puffin egg was too delicate to scan well; click on it for a larger view). The downside, unfortunately, is that it’s hard for me to imagine doing a quick journal sketch or scrawling notes on a page – the paper just seems, well… too nice. So in the end, this small journal may become more of an “art book” than a “sketchbook.” I won’t know until I turn the page…stay tuned.
Drawn In 
I wish Arches folded well without tearing and cracking. If it did, it would be my main sketchbook paper as it paints like nothing else! Still, you may find yourself with a sketchbook rather than an art book. Either will be very nice.
Laure- I used a bone folder to mark the pages before folding. That helped a lot. This is my first time using Arches in a sketchbook, so I’ll have to see how it holds up.
Elegant!
What beautiful paintings, I so agree with you about the quality of papers, it’s surprising what a difference it makes to your drawing!