main rag

main rag
 n.— «So were stagehands aligning a towering red scaffold to begin a two-day job of erecting the teal curtain, the “main rag” in theater parlance.» —“State Theatre readies for grand opening” by Chris Rosenblum in State College Centre Daily Times (Pennsylvaia) Dec. 11, 2006. (source: Double-Tongued Dictionary)