Keeping an Artist's Journal

Somehow reading this post and its accompanying comments I feel inspired to keep an artist's journal! (not promising I actually will)

Well, I already keep a personal diary, with the occasional small important item glued into it, but it's not colourful, nor suitable for reading by all & sundry!

I think the ideal could be something like the old botany books we had as primary (elementary) school students - or just entirely blank pages, of 300gsm watercolour paper preferably, so there's less buckling caused by wet paint?