When I am going home to the UK, I put my cartridges in ziplock baggies, but it is a very unsatisfactory way of doing things. I found this box in the storage aisle at Joannes and it is perfect. The cartridges fit snugly and at an angle so that it is easy to read the label. I also did dymo labels for the lid of the box in the corresponding positions. I have stored the books and overlays in a snaplid box - I only take the more complicated books with me, for those cartridges that have hidden icons and layers. (well, not hidden, as such, they are just not shown on the overlays)
