I looked for a bound book without ruled lines.
There are plenty of 'sketch books' with wire spiral bindings, but I don't need that fabulous watercolor paper and every spiral binder I have is quickly crushed so I ignore them.
Yes, the cover is 'cardboard', but it creases easily because it's not very stiff. Unpacking it, my cuff caught on the cover corner and folded over.
Very thin - 4.5mm (3/16")for 80 pages. What tricked me was the smaller pictures of the books in their 'set of three' packaging. They look thick.
I didn't buy the 8.5" x 11" XLarge because the size is harder to carry, but I will as soon as I'm done with this.