For sculpting and shaping clay, there are many sizes and shapes of knives used. While wooden knives often cost more than plastic varieties, they are more sturdy and create better lines. Either version of the knives can be used to cut into the clay to remove excess clay or to score the piece, creating a textured bond for adding a new piece. They can also be used to create a rough texture, such as criss-cross patterns, when other tools that are specifically made for creating texture are not available. Use the knife lightly when scoring into the clay, to ensure that the cuts do not go all the way through the clay.
To add a rough surface to a project, use a textured rolling pin. A textured rolling pin is a small wooden or metal cylinder onto which spikes, divots, patterns or other material are glued. The pin is then rolled onto the clay as it lies flat on the work table. The parts glued around the pin make an impression into the clay, thus creating a rough surface.
To create a rough surface, the proper tools are combs, texture mats and rib tools. Combs used to add texture to a surface come in a multitude of sizes. The teeth on the combs could be close together or far apart, round or square, or thin or thick, depending upon what the artist wishes for the rough surface. Texture mats are rubber mats with shapes molded into one side. These mats are laid upon the clay and evenly pressed into it in order to leave a rough and textured pattern that resembles the mat. The rib tools are triangularly shaped tools that work just like a comb; however, each of the tool's three sides has differently sized teeth, resulting in a varied rough surface.
Tools made specifically for use with clay can be complemented with items found in nature or around the house. These natural items, if strong enough to mark the clay, can result in a rough surface that feels just like the item. A chunk of wood bark is a one example of a natural tool that can make a rough pattern in the clay. Pressing the bark into the clay, then pulling it back out, will cause the different levels and patterns on the bark to imprint into the clay, making the clay feel just like a tree.