In our studio, we use a couple of different clays depending on the product we are making. Normally we would wedge on a canvas covered table but we needed additional clay working areas that would not get contaminated by other clays. Voila! An instant portable wedging and working surface in the form of a 2×2 foot piece of Hardibacker board.
Hardibacker board is a fiber cement board that was invented as an alternative to traditional drywall. (visit this link to see how it is used in a home http://www.onlinetips.org/hardibacker-board-installation ) You can buy this at just about any lumber or hardware store. Ours came from Lowe’s.
We cut a large piece of Hardibacker board into individual 2×2 foot squares and attached a small piece of wood to one end as a lip that would hold the board in place when used on a table. We also tend to put a piece of canvas down under the board to prevent it from rubbing into the underlying table surface. Each of our boards is marked (on both sides with a black felt-tip marker) with the clay type that will be used on it.
To prepare your portable wedging surface, coat the board with a fine layer of clay slip and allow this to dry. Then, scrape the surface with a painters trowel (plastic or metal), dust it off, and you are ready to go! The board is easy to clean and also helps dry-out wet clay.