Upvote:3
Chainmaille development and construction was surprisingly consistent from the 1st century CE onwards.
You are correct in your assumption that almost all extant maille finds are riveted, but there are examples that show butted maille where the wire is simply closed together.
In terms of construction, there are 4 types: riveted, welded, stamped, or butted. In many cases, there is a combination of 2.
For example, an early middle ages example, the Gjermundbu Maille is half welded and half riveted. The welded rings are flat (from the process of hammer welding) and the riveted are rounded (except at their pin-point).
Stamped rings, would of course be flat by their nature having been cut from foil rather than drawn from wire, as would welded (although some do retain some roundness away from the join). Maille accoutrements and shirts of butted maille are almost entirely rounded links.
Many of the examples in the Wallace Collection contains Welded/Riveted Combos, and this probably account for a high percentage of extant maille finds for the 14th/15th Century Period. Interestingly, many are a steel/copper alloy, perhaps for economic reasons.
References