I assume you're referring to Bryce 4, as Br5 allows for an unlimited number of libraries. I still use Bryce4, and I use Bryce Librarian from wolfiesden.com. I have about 30 different libraries of objects, and about 20 of mats. The librarian allows me to "swap" them back & forth from the presets folder to their storage folder. When I need to access a different one, I just have the librarian move the one I need into the User, or Tutorial, or even Boolean or Terrains spots inthe presets. Naturally, I have complete copies of the ones that belong there too. It's not as quick & handy as what Br5 has available, but it still works very well.