Dolly at the "Journal Addict" has a problem:
"On watercolour moleskine, the ink is absorbed in the texture of the pages. On that one, it’s understandable and I am not very bothered.
On sketchbook, the pages are too smooth for the ink to stay properly.
On regular – both plain and ruled moleskine, pages are too thin, so while the fountain pens work, you can see the impression on the back of the page, which sucks because I write on both sides of a page."