Asymmetrical backed artefacts typically have only one lateral margin unretouched. This margin may be straight, or gently concave in plan shape. The second lateral margin is often extensively retouched and converges on the unretouched margin to form a pointed distal end. This retouched margin may also have a gradual curvature. In some specimens the platform has been retouched and incorporated into the backed surface, giving the item a single curving backed surface opposing the unretouched margin; while in other specimens the platform remains untouched, giving the item a truncated appearance to the backed surface.

              The combination of these features determines the overall plan shape of the backed artefact. When the unretouched margin is curved the specimen has a hooked distal end. When the platform is retouched the specimen has an asymmetrical, crescentic form. And when the unretouched margin is straight and the platform unretouched the specimen has an elongated, but asymmetrical point-like appearance in plan shape. These combinations of flake form and backing location may in some instances relate to idiosyncratic or group habits, but in other collections these shapes may also reflect non-stylistic factors such as the context in which knapping was carried out, the hafting requirements, raw material properties, and so on.

            In some locations along the east coast, such as in the Hunter Valley, asymmetrical backed artefacts were retouched in two stages. The first stage removed relatively large flakes to shape the entire edge. A second stage removed numerous small flakes to trim and refine the shape of the retouched margin. Both stages were completed with a bipolar technique. The final result was often a neatly fashioned, highly standardised implement form.

              This two stage backing procedure may well be a response to low success rates in production. Many manufacturing sites show that more than 25% of backed flakes were transversely snapped during the process of retouch. In some sites this breakage rate reached 80%. Initial shaping of the elongate asymmetric form was probably carried out to give the retouched flake its overall shape, and risk snapping the artefact, before a knapper expended energy undertaking the detailed trimming of the backed edge.

              Asymmetric backed artefacts are found in abundance along the eastern sea board. In those eastern areas asymmetric forms are the only ones found in most collections. Further west asymmetrical specimens are occasionally found, but it is not clear how frequently they are the symmetrical form of backed artefact that remain unfinished or broken.

              Symmetrical backed artefacts commonly have retouch at both the distal and proximal ends, removing the platform and facilitating a high degree of bilateral symmetry. Some typologists have subdivided this class on the basis of plan shape, often distinguishing triangles, trapezes, and crescents. However no systematic studies have been carried out to determine whether these forms represent a continuum of retouching or are modalities of different shapes.

              In contrast to the manufacture of asymmetrical specimens, knappers did not always retouch symmetrical backed artefacts in two distinct stages. For example, in the case of a trapeze-shaped specimen the backing at one end might be completed before retouching the other end.