Expanding on my earlier comments about a steamed bow blank stretching unequally as it is bent around a bending jig, I wanted to address the issue of one piece hand-rests versus two piece bow/hand-rest laminations, and the effect of each method on the assembled chair.  I've noticed a number of Windsor chair-makers who make their bows and hand-rests out of a single riven piece of stock. They know the "ideal" length of a particular bow blank for a given chair design and bend the same length of stock time after time. My problem with this method is that it ignores a number of variables that creep in and vary both the length and symmetry of the bow. Some of these variables are; small differences in the compound angles drilled for the arm posts between one side of the chair and the other, the tendency of one side of a bow blank to stretch more than the other (explained in an earlier post), the general orneriness of a given bow blank (differences in grain), the "sproing" as an unclamped bow relaxes when removed from the bending jig, and even the method used to mark out the holes drilled in the arm for the arm-post tenons, any or all may effect a bow's symmetry. And differences in shape effect the gap between the back edge of the seat and the inner side face of the arm bow. These comments are particulary relevant for Comb-back and Sack-back Windsors where the arm bow extends beyond the back edge of the seat and this distance, or gap, determines the angle of the chair's back. Shorten or lengthen this distance and back angle changes.  For the my Sack-back Windsors, as an example, I want an inch gap between these two points as measured with a framing square laid front to back on the seat. This measurement is important because it determines the angle at which the spindles in the arm bow fan out and back from the spindle deck. In a single chair, whether the gap is actually 3/4 of an inch, or 1-1/4 inch, while effecting the angle of the chair's back, isn't usually noticable because the chair is a one-off and it will still be more or less comfortable.. For a batch of chairs, I find that it is an absolute "must do" to fit each bow individually to a specific chair in order to determine the sweetest curve side to side and to create a consistant bow to seat gap, and back angle in the set of chairs. This means that my holes for the arm-post tenons vary from bow to bow, and the glued on blocks from which the hand-rests are cut vary as well. I will talk about how I do this in a future post. Thanks for stopping in.