I'm working in an 8" square sketchbook I made. The pages are an assortment of watercolor papers, all shapes, sewn together to make nearly full sized pages. I save all my paper scraps as well as paper samples (waste not, want not) and this seemed to be a good use for them. Some papers work better than other. This first page is 7.5" x 3.5" and is sort of the introduction page.
I did this page yesterday and am NOT happy with it. The pots are okay (I'm working on ellipses which are hard for me) but the pen I used wasn't waterproof so the minute I started adding watercolor the black ink made the page gray preventing me from painting bright colored tulips.
Perhaps you can get a better idea about the sewn together, pieced, pages in this example where the larger but shorter section on the right was zigzag stitched to the narrow piece on the left. I rather like the look.