Linen canvas for proofing bread is mainly used in France and is called (couche) meaning: layer, diaper, lay down or verb go to sleep (coucher). There is a famous song (voulez-vous coucher avec moi ce soir), “Do you want to sleep with me tonight.”
Made of natural flax fibers with no chemical color or setting used, linen is the best material for proofing bread. Linen is very durable, but flexible and light, which allows the folds needed separating the shape of dough. Shaped loaves of bread are placed in between the folds of linen to help the bread maintain its shape during proofing, reduce the amount of space needed in between the loaves, and prevent the loaves from proofing into each other. Linen will absorb the excess moisture of the dough and minimize stickiness during proofing or overnight retarding but will not dry it out, giving a nice thin crust. The fabric can last forever if scraped or brushed after every usage, and then hung to dry before using again. If washing linen, it must be cold water and hang dry. It might shrink.