http://www.cliffsnotes.com/literature/o/the-odyssey/critical-essays/major-symbols-in-the-odyssey
"The shroud that Penelope weaves for her father-in-law, Laertes', eventual funeral symbolizes the cunning with which she confronts the suitors. She lacks the power to fight them with physical strength so she wards them off with her wits. The suitor Antinous bitterly tells the story of the shroud to the assembly in Book 2: Penelope devoted herself to the shroud for three full years, promising she would choose a husband when she finished. By day, the queen, a renowned weaver, worked at a great loom in the royal halls. At night, she secretly unraveled what she had done, deceiving the young suitors. The ruse failed only when Penelope was betrayed by a disloyal maidservant."