Designing magic props is unlike designing anything else. When deception is the North Star, the path forward often runs counter to traditional craft. Sometimes this means the punishingly thin walls required to make a shell nearly indistinguishable in size from the object it imitates and conceals. Other times, it means cleverly hiding a mechanism while keeping it effortless to operate. Most classes will teach that a characteristic of good design is discoverability (a Norman door, notoriously, lacks this). Magic inverts that principle.
About two years ago I purchased Nicholas Lawrence’s SharpShifter, a utility prop that pairs with an un-gaffed Sharpie marker. I enjoyed it because it allowed for a deceptive presentation of Gregory Wilson’s Pointless—the tip of a Sharpie is larger than that of a Bic pen and its vanish and reappearance feel more magical. It might also fool audiences who are privy to the now ubiquitous pen-through-dollar gaff; the ergonomics of a Sharpie just wouldn’t allow that method to work.