I have had a quick google and it looks like Clairefontaine paper is available in the UK also! I want to try it out, I'm always interested in new book paper. what is the grain direction like on the ones you use? I know not everyone cares about making sure the bookpaper is the right grain direction, but I like to try to make sure it's the right way around.

yes! I also always use a moisture barrier (actually just two sheets of plastic that used to be an 'envelope' for some decorative paper that I've cut to size) and something absorbing (actually just some cheap cloth from the grocery store cleaning supply section! it's absorbent and thin enough that it doesn't mess up the book in the press) because I found out the hard way that not having anything like that definitely messed up the rest of the textblock.

for the recycled papers in this post where I mentioned using this method for sure it seems like the recycled paper WANTS to be wet or very easily absorbs moisture and warps and starts falling apart, so it's extra important to not miss this step! the adhesive, whether paste or PVA (or EVA which I've also used a few times) seems to hold the paper together pretty well once it's dry again it's just while it's still wet from the adhesive one needs to be careful.