This first pair may not be boned at all. The appearance of channels may be the result of the overlapped pieces of leather forming the body. They are lined with linen, through which you can see the wear pattern of the "channels" through the back. This is consistent with a move towards "softer" stays in America (and England, and France, and...) at the end of the 18th century as well. Verdict? Not sure. But it makes me want to attempt to make a pair like this.
Created around 1750
Created in 1763, quite specifically!
Back of the same pair:
No more information is provided, other than the date of manufacture for the above pair, which are the most humble of those that I found.
This last pair are the most interesting to me. They are described as "Stays" on the website, whereas the above three are listed as "Bodices" or "Waists." ( All terms appear in various groupings under the heading of "Corsets.") These are of softer, chamois leather and are cut into "10 thin sections with 20 channel stiffeners of whalebone". Clearly, they are front-lacing as are the other three pairs. However, this last pair appear to close by symmetrical cross-lacing rather than spiral lacing like the others. The website states that "the edges folded in and sewed to the lining and 8 pairs of new eyelet has prylats* and edge stitched" which, you know, clears things up considerably.
*EDITED 7.7.13: Reader Anna-Carin clued me in on the correct interpretation of this word. "The proper translation of 'prylats' in this context, is that the holes have been made with an awl." Thank you again!
Created 1750-60, possibly worn until 1795.
The site also specifies that two of the original women who wore these stays (yes, two) were the wife and daughter of a reverend, respectively and that "peasant women did not wear these." That's really bloody fascinating to me. Obviously, they are more sophisticated in design and construction and the materials are less crude. Yet they were made in proximity to the other three pairs, at least two of which were worn by rural, farming women who definitely put in a full day of work each day.
It is very compelling to see these well-worn, gently modified and customized Swedish leather stays in such wonderful condition. Speaking only for myself, it casts a bit of light into the wear-ability of leather stays for hard working and less-affluent women in this country as well. Cassidy at A Most Beguiling Accomplishment wrote a great post this past week about the accuracy and variance in interpreter's costuming at historic sites. It made me think about some resistance I've noticed to the notion that rural, "backwoods" women could have worn stays of any kind during my encounters with the local reenacting and historic interpretation community in this area. The main argument against the wearing of stays is that they are "uncomfortable". (There also seems to be a rather disturbing perception that stays are basically corsets, and that corsets are basically lingerie, ergo only buxom and flirty younger women should wear them.)
This settles nothing, but it certainly makes the argument more interesting!
And check out the Nordiska Museet! Thar be gold in them thar hills.