This is a different take on the Thinline from the envelope style. This one is exactly like the Standard except for thinner panels and two buttons for adjustment rather than four. It won't have the capacity of the Standard, but it might be a touch more than the envelope style Thinline.

The Bookwarden is an absurdly expandable and overprotective slipcase for your literary travels. Originally conceived of after yet-one-more book cover was bent in my backpack, I wanted a portable case for whatever book(s) I might be carrying, but also one that would allow me to remove one book from the case without having to remove all the books (and case) from my pack.

I daily carry one with whatever book I'm currently reading (in my lunchbox, no less), and when traveling I tend to load it up as I'm not a light literary traveler. Once I'm to my destination the Bookwarden makes for a nicely organized travel bookshelf as it stands on end when fit with a couple of books or more. 

While I prefer my book books, you will occasionally find my Kindle parked between a couple of paperbacks, or perhaps a journal or sketchbook. I'll even slide various and sundry things under the shock cord straps from time to time. 

The Thinline was designed to be as unobtrusive as possible and therefore used as a single book sleeve or with two or three thin books. 

The Bookwarden fits books up to 6.75" x 9.25" and will expand to hold upwards of 2" of books.