Popular Pottery Techniques
Pinching yourself differentiating between the soft slab and hard slab? Coiling your brains around throwing and molding? Find out what some of these pottery terms mean.
Within the two broad methods of hand building and wheel throwing, there are several different ways to create pottery. Popular techniques include:
Pinching – Pinching is one of the best, simplest, & most direct ways of shaping clay. Pinch Pots are created by patiently & steadily poking, pinching & pulling a lump of clay into form. Lumps are evened out by applying steady pressure & tears are cut away.
Coiling – Coiled Pots are created by gradually stacking & joining “snakes” of clay on top of one another. If the clay is very soft & moist, coils can be added directly, but if the clay is relatively dry, contact surfaces needed to be scored & slipped to ensure a strong join.
Press Moulding – Soft slabs or coils are pressed into concave molds. The inside of the application is then trimmed & decorated, & the piece is left to dry until it is stiff enough to support its shape and weight. It is then popped out of the mold for the exterior surface to be decorated & for finishing touches to be added.
Slump Moulding – The mirror image of press molding. Soft slabs or coils are laid over convex molds. The outside of the form is then trimmed & decorated, and the piece is popped off the mold before it gets too dry that it shrinks around the mold. If the texture is desired on the interior surface, the soft slab should be textured before it is laid over the mold. Interior surface design can be performed after unmoulding.
Slip Moulding – Clay slip is poured into multi-part plaster slip molds. Excess slip is poured out after a certain period. Upon unmolding, seams are reinforced with coils if necessary. The piece is then trimmed and decorated.
Soft Slab – Soft tiles are made from clay that is very moist and plastic. Soft slabs can either be rolled out to a uniform depth or created by throwing a clay disc with irregular textures at a flat work surface at an oblique angle a couple of times. The slabs, or pieces cut from them, are then quickly shaped into, over or around molds or around the crumpled paper. Scoring and slipping may be required on joins as the piece dries out.
Hard Slab – When soft slab that has been turned out is allowed to dry until it is leather hard, it becomes hard slab. Pieces cut from this relatively stiff clay are joined by scoring and slipping to make geometric, precise work such as boxes.
Throwing directly on the wheel head or a bat – This is possibly the most common wheel throwing practice in Western studios currently where the emphasis is on creating one-offs. A wedged piece of clay is centered, coned and then thrown into a symmetrical, circular shape, generally a cylinder or bowl. It is then cut off the wheel head and allowed to dry until it is leather hard, then turned upside down and returned to the wheel head to be trimmed. Only one piece may be thrown from one piece of clay.
Throwing off the hump – More common among production potters creating limited designs in volume runs. A large lump of clay is attached to the wheel head, and several pieces are thrown in quick succession from it. Only as much clay as is needed to make each piece is centered, coned and thrown from the top of the lump at any one time. This requires a practiced hand and a good eye, especially when cutting the finished piece off the hump. Clay is continually added to the mass on the wheel head as it is used up.
Many potters combine several of the above techniques in creating their pieces. For instance, in How To Throw a Piggy Bank, several wheels threw pieces are altered by cutting before being joined together. Handbuilt elements are also added.
Experiment and find the techniques that you enjoy the most, then combine them to create your dream piece.