A method is provided of using morphologically specific free-floating structures as Standards in the pharmaceutical industry to test objects in drug containers. These structures are micropatterned according to a desired pattern. A container is filled with a defined number of the standards, which then can be used as a standard reference for testing other drug products held in a drug container. The testing pertains to optically identifying structures in the drug container that can be similar in size and shape as the standards, or that can be different in size and shape as the standards. The advantage of the method is that imaging systems with tracking algorithms that count and track sub-visible and visible particles in solution can be used to identify e.g. glass flakes and other foreign particles by comparing them to the shape and size of the standard reference particles.