Probably the single most valuable technical diagnostic is the manner in which holes were made. The former technique seems to have been the earliest, and been less common later on, but it seems to have lived on for the production of small-diameter holes. In holes which are bored from both sides, if the resulted hole was not polished internally, it is usually possible to tell, from the traces left where the holes from each side met, which technique was used. Hollow-boring resulted in a small ridge where the two holes met, with the sides of the ridge meeting at a fairly obtuse angle. Another key technical indicator is the way in which blade cutting edges are formed.
Some edges are perfectly straight, and others gently curved.
The Dawenkou and Logshan cultures used a techique of hollow-ground edges which results in edges which are perfectly straight, and a gently curved back line where the edge facet transitions into the blade face. Along with the absolutely conical single-sided holes, and very flat and highly polished faces, these make Longshan blades absolutely distinctive in all Chinese archaic jade work. The Liangzhu and predecessor cultures have blades with curved edges, and the facets of the edge are convex curves which blend into the blade body with no noticeable transition line. It is not clear exactly why these regional differences in technique exist, and indeed we may never know for sure, but we can posit a number of hypotheses. One possibility is that jade working appeared completely independently in different areas, each with a dissimilar, and indigenously developed, set of jade-working techniques.