MUSEUM GEL- This is the best choice for anchoring glass or crystal objects as it is invisible on clear objects and glass shelves. Roll it into little ball, set the artifact in place, and the gel sets in hour or so. It is reusable and non-toxic. Museum gel is also the best choice for items which are frequently moved. The gel is not susceptible to aging, though replacing it every time you clean the objects (or 3-4 times a year) is suggested. It is available in 4-oz. containers.