What happens to individual items when you cast a permanent shrink item on a group of items?
Shrink Item can be found in the Player's Handbook page 279:
Shrink Item Transmutation Level: Sor/Wiz 3 Components: V, S Casting Time: 1 standard action Range: Touch Target: One touched object of up to 2 cu. ft./level Duration: One day/level; see text Saving Throw: Will negates (object) Spell Resistance: Yes (object)
You are able to shrink one nonmagical item (if it is within the size limit) to 1/16 of its normal size in each dimension (to about 1/4,000 the original volume and mass). This change effectively reduces the object’s size by four categories (for instance, from Large to Diminutive). Optionally, you can also change its now shrunken composition to a cloth like one. Objects changed by a shrink item spell can be returned to normal composition and size merely by tossing them onto any solid surface or by a word of command from the original caster. Even a burning fire and its fuel can be shrunk by this spell. Restoring the shrunken object to its normal size and composition ends the spell. Shrink item can be made permanent with a permanency spell, in which case the affected object can be shrunk and expanded an indefinite number of times, but only by the original caster.
The spell can explicitly be used on a group of objects as the description uses a burning fire and its fuel. So there shouldn't be any issue casting it on a chest full of stuff. But what happens if you make that casting permanent?
I doubt you'd get a bunch of objects, each with their own permanent shrink item spell on them... would you? If not, what happens when you remove an item from the chest then try to activate the spell? Does everything in the chest shrink but the removed object doesn't? Will the spell only activate if all the items are present?