Broad knives made of elk scapula were widespread in the Mesolithic of the forest zone from the Eastern Baltic to the Trans-Urals. Operation sequence of their manufacture was rather standard. The ridge of elk scapula was knocked off, and its surface was planed by carving, scraping or whittling, sometimes smoothed with an abrasive slab. One edge of a scapula was cut off and sharpened by longitudinal whittling with a flint knife. The joint was flattened or broken off. The distal end of some knives has a pair of perforations pierced through or rarely drilled. Use-wear analysis conducted by the author showed that broad knives made of elk scapula were used mainly for hide processing, and some were used for removing bark from tree trunks. Most of them are not decorated. Rare knives with ornamentation or abstract geometric engravings from sites Stanovoye 4 in the Volga-Oka interfluve and Veretye 1 in the Eastern Onega region according to traceological data were used in the same manner as undecorated ones. Engraving of ornamentation, and especially complicated geometric designs demanded substantial amount of time and labor. Such images are single and not repeated even among materials of one site and one culture. This indicates individualization of the world perception and its representation among separate members of Mesolithic communities. Evidently not only working characteristics of a tool were important for them, but also its appearance. Probably complicated abstract images engraved on broad knives had definite, possibly sacred meaning. But at the moment we cannot offer its reliable explanation.