If you are maintaining loan files, you are already capturing this information in regards to an object's history. At the most, if you wish to record the shipping label in association to a loan, then photo document it and attach it to the loan file, or photocopy it and put that representation in the physical file. Assuming these have an adhesive backing, you would be expending space in your files for an unstable label that requires some type of encapsulation or barrier. In a sense, you are trying to elevate a shipping label to collection level care.
Remove the labels from your crates, you do not want loan items arriving to the wrong destination.