Our secretary ordered these cups and I as a communion steward and head of the Altar Guild do not like them at all. Not only do they stick together, but they stick in the trays and people have a hard time getting them out as we do not distribute the cups they take them out themselves. I think you need to improve on that.
We use these cups all the time now. I've shopped around, and this is the least expensive place I can find them. The cups look like glass and are convenient to use. One reviewer noted their tendency to stick together. They do, but after applying a firm rocking motion to the cups, they come apart quickly.