Add to the confusion the wide variations in ring sizer sets, the
choice to use wide band or regular sizers and the different places on
a ring mandrel where people measure-- some use the leading edge,
others the middle of the ring-- and a "standard" or "atomic size" or
"Greenwhich mean size"-- really becomes moot, in my opinion. I've
been having people measure the leading edge on the mandrel and then
use digital calipers (outside edge of the blade aginst the wide end
of the mandrel taper) to give me a millimeter size. It works great--
if our calipers match...
Sometimes I send out a ring mandrel to a gallery for them to use. I
have already measured a size with my calipers and that becomes my
constant or zero against which I can check the consistency of their
calipers ( I have the gallery measure, say, a size 8 and compare it
to my recorded measurement of a sized 8). This helps.
For long distant private clients, I have them give me a size range
and then I send out 6 sizers within that range, either wide or
regular, and have them mark with a twist tie the sizer that works
best for them. I include a return mailer.