I hate to sound like a salesman, but if you maintain a sketchbook, moleskin is definitely the way to go. You can use pens on them without any risk of it bleeding through to the other side of the page, so no wasted space. They are sturdier that most other sketchbooks too, which is good for me so the edges won't fold because I just keep it in my backpack. Anyway, click below and buy one. Do it.