Someone asked, so I'm responding here, in case anyone else is wondering. The little art journal I'm working in is from Hobby Lobby. Ir measures 3 1/2 by 5 1/2 inches. It cost $2.99. It works well with pencils and can be painted on with acrylics. Not good for watercolor as the pages will warp. Also good for collage if you remove some pages. Some of the juicier marker pens bleed through the pages.
Right now since I'm working in pencil, my challenge is to stop the soft leads from one page from smudging across to the opposite page. One of my first assignments working in archives, was to interleave archival tissues cut to page size into each of John Muir's journals. It was the practice in those years to do this, to prevent further smudging. Muir had carried them in his pockets in the field and they held up remarkably well, considering the use they had and the conditions in which they traveled. (this image is a page from one of his journals. They can all be seen on the California Archives site, you can google it) Most of his drawing are still very sharp images and are useful in research and illustrating the geology and flora of the different areas and times. For instance, the sketches he did of Glacier Bay are the first views we have of that area and scientists now compare his detailed drawings to how the Bay looks now. I digress.
I am challenged now by what to interleave into my own little journal. I think I'll use deli wrap instead of tissue. It seems like the finish of the pages with that light wax will be more protective. I could spray them with a sealant. But, I try to use "green" methods when I have a choice, and adding chemicals to the air and pages is not my first choice.