Retouched Flakes

When a flake is trimmed or reduced by flaking, archaeologists refer to it as ‘retouched’. Retouching was often done to sharpen or repair a tool, or to modify its use.

Retouching was practiced by our earliest stone-flaking ancestors. These tools are found in Oldowan sites at Olduvai Gorge in Africa, and they were particularly common in the Karari Industry, dating to ca. 1.4 million years ago. Retouched flakes were an element of most stone-flaking technologies right up to the recent past.

Retouching was most often applied unifacially, by striking blows against the flake blank’s ventral surface to remove flakes from the dorsal surface. The edge-angle between the ventral and dorsal surfaces is ideal for this. Occasionally flakes were retouched bifacially, to both faces along the one edge. Retouching was usually done by percussion using a hammerstone, although sometimes pressure flaking was used.

Retouching was done for a variety of reasons. Although a stone flake is sharpest when first struck from a core, retouching can repair an edge damaged or worn through use, or gummed-up by the material being worked. Conversely, retouching a razor-sharp edge can steepen it, making it less likely to cut the fingers, so in this case retouching was applied opposite to the cutting edge.

Flakes were sometimes retouched to create tools with a specific shape. For instance, a Neolithic tool called a ‘fan scraper’ was retouched by percussion or pressure flaking applied to one face. These were traded widely in northeast Africa and Western Asia. Similarly, Aboriginal people in the recent made ‘tula adzes’—a type of retouched flake—and exchanged them for a narcotic plant called pituri.

Retouching was often done to steepen the edge of a flake. The edges of an unmodified flake are razor-sharp and low-angled, like a modern kitchen knife, and the process of retouching steepens this edge profile. A steep-angled edge profile is more robust, and particularly ideal for scraping tasks. Retouched flake scrapers continue to be favoured over their iron counterparts by hide workers in Ethiopia, as the stone is less likely to cut the hide during defleshing. Scrapers like these were often hafted onto handles to increase the force that can be applied to the tool. An ‘end scraper’ is a flake retouched at the distal end, and these were used as hide scrapers in North America and Europe.

Flakes often served as blanks to work into other types of tools, such as backed microliths and bifacial knives, spearpoints, and arrowpoints. In the Late Acheulean period, some 1.5 million years ago, our hominin ancestors made exceptionally large flake blanks and shaped them into bifacial handaxes and cleavers. Although these are retouched flakes, archaeologists often apply more detailed classifications to complex tools made on flakes.

In many stone-flaking technologies, large flakes were made at the quarry sites where the stone outcropped, and were carried away for use elsewhere on the landscape. A transported flake blank served as both a useful tool in its own right, and as a core for striking off additional useful flakes. This type of retouched flake is sometimes called a ‘core-on-flake’, or ‘flake blank core’. Flake blank cores were common in Australia and other parts of the world, and this approach to toolmaking was practiced by Homo floresiensis (the ‘hobbit’) at Liang Bua Cave on the island of Flores in Indonesia.