We have both a permanent and a study collection.  Permanent
    collection objects are accessioned and are not provided for
    hands-on use.  As additional gifts are offered, we often allocate
    duplicate or damaged items to the study collection.  This
    collection is for loans to low security sites like public and
    university libraries, etc.  We also loan these objects for
    hands-on activities in schools, science fairs, etc.  The items are
    not formally accessioed (however, they are given via deed of
    gift).  I mark each piece with tiny letters in ink, "STUDY."  When
    an item in this collection is broken or damaged from use, it is
    discarded.  Amazingly, few items get damaged so our study
    collection continues to grow.


    Hope this is helpful.

    John Handley