The Fabric itself is created in an Arcane Workbench by surrounding 1 piece of wool in the center section with 4 string in the right, left, top and bottom middle sections, along with 5 of each type of Vis. This yields a single piece of Enchanted Fabric, meaning that while the wool may be easy to obtain, for a full set of Thaumaturge's Robes you'd need 96 string, something much easier to obtain using Entropic Processing than by hunting spiders.
Thaumaturge's Robes are a set of armor consisting of the Goggles of Revealing, Thaumaturge's Robe, Thaumaturge's Leggings and Thaumaturge's Boots, all of which provide a Vis discount totaling 10%, are highly durable and enchantable, and, excepting the Goggles of Revealing, can be dyed. On average, the Thaumaturge's Robes set is approximately 5.25 times more durable than normal leather armor, but provides the same amount of protection - 7 armor points. Enchanted Fabric is shaped into its armor pieces just like any other, but must be made in an Arcane Workbench, using 30 Aer, 25 Aqua and 20 Terra Vis for the Robe, Leggings and Boots respectively.