What i love about these cases, is that they have an extra zipped pouch at the back. This means that if you are going on a journey, or to a crop, you can carry 24 of your fave colours plus some images to colour, all in one pouch.
Folded up the case measures 10 1/2 x 7 inches, so they are small enough to carry in your bag, but big enough to cary other pens that you may use for your crafting too.
They are only about £6 each, well worth it when you've just paid out a small fortune on the pens themselves. I got mine from here at Cult Pens, i got my pens here too.