The different pharmaceutical forms and the variety of packaging that make them available to the user generate gestures, interactions, and usage behaviour, which are worthy of interest to those interested in reading the objects’ formal attributes and the influence exerted on those using them. In the world of medicines, oral solid blister forms represent an interesting case due to the complex use dynamics dependent on both the ‘content’—the medicine—and the ‘container’—the blister. Starting from observing how patients use medicines in their home environment, this chapter focuses on how the characteristics of oral solid forms (e.g., tablets, capsules, packets) and those of blister packs can induce incorrect or non-compliant use behaviour. These behaviours are especially characteristic of older people.