I had intended to suggest overlaps between the various types of beads manufactured with the use of +/-, but I gather that wasn't clear; oh, well.

Beadiste, I've wondered why you have referred to cinnabar beads as waxy? I skimmed the article on sealing wax you posted, but the only reference to cinnabar I could find is one sealing wax recipe; I had assumed the cinnabar was added for color only. Do you think the bead material is petroleum-based (as is wax)? Are you referring to the same type of greasy finish some glass beads are said to have? (I don't know what makes greasy glass beads greasy so this is a leap.)

To refine the below, per Beadiste's comments; further comments on the below?:

1920s-1990s +/-: Type or types of synthetic cinnabar resin applied in layers over metal or wood bases and then carved. Waxy finish. Used in Yangzhou workshops. Colors: black and red, green, yellow, and turquoise.

1970s +/- to present: Waxy-looking resin cast into molds; objects have obvious mold seams. Sometimes only roughly formed in molds then carved to completely hide the joints.

1990s-present +/-: Different type of synthetic resin came into widespread use. Brighter red than the above, with a plastic, shiny appearance. Commonly created in two-part molds, with visible joint marks.