Given the high quality clamshell cases being offered with the HC Super Deluxe CoH, and the occasional slipcase or clamshell case offered with high end Tolkien books on eBay and from antiquarian dealers, I have been thinking recently that I have some books I would like to give an extra bit of protection without modifying the book (no rebindings, no reproduction dustjackets, etc.)

Anyone ever done this, and have recommendations of binders that do this sort of work? Google searches offer way too much noise to information so I haven't found anything really useful online yet.

Any opinions on this? Do you like books that have slipcovers or clamshells (original to the book or added after)?