Scamorza is what happens when you take a fresh stretched-curd cheese and choose to dry it instead of eating it young, and that choice defines the panino built on it. Shaped into a pear with a pinched neck and hung to firm, scamorza loses the milky looseness of mozzarella and gains a denser, springier body that holds a slice and, more to the point, melts cleanly without weeping. Often it is lightly smoked, the affumicata, which adds a low woody note over the mild curd. The defining property is meltability with structure: this is a cheese chosen because it goes molten and stretchy under heat while a fresh one would only flood.
The craft is heat managed against a cheese that rewards it. Sliced and laid in bread, scamorza is meant to be warmed, on a grill, under a press, or in a hot panino, until it pulls into strings and glosses the crumb rather than seeping out. Drained dryness is the point: because it carries far less water than mozzarella, it will not steam the bread soft before it melts, so the crust can crisp at the same moment the centre flows, the timing problem every grilled cheese poses, solved by the cheese itself. The smoked version wants the bread plainest, since the smoke is the seasoning. The bread is a sturdy roll or ciabatta, firm enough to take the press and the melt. It is eaten hot, the instant the cheese is molten, when the stretch is at its longest.
The variations are mostly about smoke and what is melted alongside it rather than the cheese itself. There is the plain bianca for a cleaner milk note, the affumicata for the woody edge, and the version with a slice of cured meat or grilled vegetable folded into the melt. Those additions each pull the sandwich toward a different idea and deserve their own articles rather than being crowded in here.