Been working out the character kinks on my Librarian Wizard (known so far as "the Archavist") in our Magical Spokane game.
Problem 1: Nothing he uses should be able to harm books unless something extremely unusual happens.
Problem 2: Even if something unusual happens and he finds himself backed up against, oh say, a bookcase (worst case scenario in his eyes) his shield, at the least, should not harm any nearby books.
Problem 3: If his defensive rote works successfully, it should damn well not put a mark on anything inside the library. Especially the books.
I found an answer to the above problems in the 2nd Edition D&D Psoioncs Handbook. I can't remember the name of the power, but there was one that created a barrier around the psion consisting of "elastic air" that contracted when a projectile attempted to pass through it. I figure his rote affects the air around him changing its properties to increase the action of friction on objects passing through it, slowing them down and eventually stopping them completely. Visually, things like shrapnel, bullets, etc will hit the shield and the impact would send circular ripples through the area of the defensive field as the kinetic energy of the projectile was bled off and dissipated (think Neo stopping bullets in the Matrix).
After the magic creating the shield dissipates, everything held in the air just falls to the ground.
Anything with its own locomotive power could just swim through the shield I guess, but anything small would have a hell of a time breathing (goddamn bugs).