Leaf wrapped around the bunch to hold the filler together and give the cigar its shape before the wrapper goes on. Binders are chosen for tensile strength and combustion rather than beauty, and often come from thicker primings or from leaves rejected as wrapper.
Why it matters
Binder governs how evenly a cigar burns and how well the bunch holds its draw; a weak binder shows up as a split side or a lopsided burn line.
In context
"We moved to a Mexican San Andres capote to slow the burn down a touch."