Here are two series of small folders with icons in the shape of books that can be stacked together in groups of ten.
I have seen many similar schemes with drawers and cabinets for grouping four or eight folders together, but none for handling groups of ten. I often find myself working with files that need to be orgainized by base-ten numbers. For example, I often group files by the year in which they were created. The Mac is ten years old now and, yes, I have files going back almost that far. Bookshelf Folders are perfect for this.
I have created two varieties, plain and alternate, so that I can distinguish, for example, ordinary folders from compressed archives.
I hope that these folders are of use, and may all your desktops be clean.