Related to silk or silken material. Silk was one of the most precious trade commodities in the ancient world, often associated with luxury and wealth.
Revelation 18:12 lists silk among the luxurious goods traded by Babylon the Great — the world system that seduces nations through wealth and commerce. When Babylon falls, merchants weep because no one buys their cargoes anymore, including silk. Material luxury is temporary; only spiritual riches endure.