I like to fume the wedges and pins for my oak rockers ahead of the rest of the chair to create contrast. When I opened the tupperware container that I use for this, to my surprise, I had left it full of pieces and actively fuming for about 6 months!! As you can see below, with a freshly cut piece for contrast, the parts are downright black.
I've always wondered how far I could take the fuming and how long it would take to get the maximum depth of color. I use janitorial strength ammonia, which doesn't have the kick (or as much danger) as the blueprinting stuff. I suppose some experiments are called for, or, I could just make neglect a part of the process.
Below, you can see that I've made a pattern using my fancy new profile gauge and used it to carve the seat on my latest chair. It was interesting to use such a distinct reference, I liked it.
Looking at many chairs to arrive at the shape brought to light some interesting notions. My goal is to carve a seat that is deep enough to avoid pressure spots, but also broad enough to allow easy movement. Then there also is the issue of removing enough material from the front of the seat so that the circulation isn't cut off to the sitters legs. Depending on the style of seat, this can be more or less difficult to achieve. I must admit, those upholsterers might have some advantages!
Once the chair is done and I can truly test the shape out I'll post a measured drawing of the templates that I used.