Blade Technique (Sekijin-giho) (石刃技法)
The blade technique is a technique of removing vertically-long lithic flakes from stone, which emerged during the upper Paleolithic period and characterizes the period. This technique enabled lithic flakes to be standardized and mass-produced.
In Japan it was developed from about 30 thousand years to 15 thousand years ago along with knife-like flint tools. It is a technical indicator that marks the beginning of the upper Paleolithic period in North East Asia. The blade technique is considered as one of the innovative techniques that spread from the Eurasian continent to eastern Asia by way of Altai and Siberia.
The blade technique is thought to be an important factor in the research of human evolution and spread of Homo sapiens.
The outline of the technique
First, a raw stone (base rock material) is cracked roughly into round slices to prepare the preform for the lithic core, after which the raw material is processed to form a lithic core, which is then struck consistently from the same direction to remove all same-sized vertical lithic flakes from the core. These lithic flakes are called flint blade, which are secondarily processed into a variety of stone tools. Most of the secondary processing was to take the edge off by smashing and reduce them to knife-like flint tools.