"It shrivels the thoughts, rather than the solid matter."
The Shriveling Shroud is a bewitched Shroud made by Dorcas Loom in the sixth book. It weakens it's victim's endowment, causing the person to lose his/her endowment. It was used on Billy Raven who lost his talent for speaking to animals. The enchantment wore off later on, as to Billy was not wearing it continuously. According to Arthur Saltweather, the shroud shrivels thoughts through the solid matter. It is described as a "ghostly grey shroud" and a "dreadful grey thing". Dorcas had knitted the shroud on large needles very carefully and presumably dipped it into a potion by, like Venetia Shellhorn, dips a finger into the potion and lines it carefully along with her knitting or sewing. When it fell on Billy, it pinned him to the ground like a net of steel, proving it was very strong. When a shrivelling shroud is removed, it is rather difficult to draw away because it clings tight and creeps up on another area when one part is brought back. After Treasure and Arthur move the shroud away, Arthur takes, possibly preventing someone from getting hurt, or using it again. A shrivelling shroud is similar to a shrivelling shrawl, knitted by Lola Defarge, a shrawl that is also like the shrivelling shroud, which takes away an endowment and shrivels the thoughts.