Infusion was the worst step of wand-making. More time consuming than selecting the core materials, more physically draining than hollowing and carving the shafts, and more sensitive than either. Core selection and shaft design were by their nature subjective. They composed the art of wand-making. Infusion, however, was the science. Precision was paramount. Anything less than perfection meant failure: a waste of time, materials, effort and, ultimately, lost profits.