This flint blade was struck from a bidirectional core.  The blade dates to the Boreal climate epoch, during the Middle Maglemosian phase of the Mesolithic period of Scandinavian prehistory, ca. 9000-9,800 BP.

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The negative scars on the dorsal surface of this large blade show that it was struck from a bidirectional blade core, placing it in Maglemosian Technogroup 2.  The diffuse bulb of percussion and bending initiation suggest a soft hammer, such as antler, was used to detach the blade from the core.  However, differentiating the knapping techniques on individual blades is difficult because indirect percussion and soft-hammer direct percussion can both result in blades with diffuse bulbs and shallow platforms, as demonstrated by replication studies.  Technique is more reliably determined at the assemblage level—by comparing the range of variation in blade attributes between sites—rather than on individual artefacts.

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Maglemosian sites are found in Denmark and southern Sweden.  People during the Maglemosian were adapted to a dynamic post-glacial mosaic of tundra, boreal forests (taiga), and, eventually, deciduous forests.  In the earliest Maglemosian (Technogroup 1), thick macroblades were struck by direct hard-hammer percussion from single-platform cores.  In the middle part of the Maglemosian (Technogroup 2), macroblades were struck by direct hard- or soft-hammer percussion from single-platform or bidirectional cores.  Bidirectional core technology involves striking flakes from either end of the core face, and it is an ideal approach for overcoming knapping mistakes such as step- or hinge- terminated blades.  Because of this, bidirectional blade cores were independently invented in various parts of the world.  They occurred in Upper Palaeolithic Europe, and by ca. 9600 BP bidirectional ‘naviform’ core reduction became the  blade-making method of choice in the Levant, Anatolia, and the Tigris-Euphrates Basin.