One thing I should comment on that is not discussed by the literature is the difference between a structured ("shaped") vs a unstructured ("soft") approach to cutting the chest canvas. Structured
The body canvas will be made of wool and hair of decent weight (but still suitable to the weight of cloth chosen). The canvas is cut on the straight.
A structured canvas will have the chest piece extend down further and the front edge may also be extend down the length of the roll line reaching the buttoning point:
Note how the chest piece is extended so as to reach close to the waistline.
The other feature of a structured chest piece is that it is cut on the straight (example from Jefferyd's blog
The density of the pad stitches is also much higher. Here is an extreme example from the Bunka men's tailoring book
Note how close the pad stitching is. After horizontal rows of pad stitches are inserted below the shoulder, a second row of vertical pad stitches are inserted around the armscye area, and functions as an armscye reinforcement.
A structured chest also has more cuts and wedges in it, to give it shape. This is possible because the canvas is heavy enough to be able to take multiple cuts without being excessively weakened or robbed of its spring. Furthermore, any cuts in the chest piece can and should be strengthened with additional layers of reinforcement. In this case, there are two additional
layers of shoulder reinforcement cut from chest canvas in addition the the main chest piece:
That means that there are three layers of chest canvas in the shoulder plus a layer of body canvas and domette.
has used only one layer of shoulder reinforcement that compensates for any weakness created by the cut in the shoulder of the principle chest piece:
The additional shoulder reinforcement allows for the opportunity to open an additional wedge at the neck, thus giving the canvas more shape. It is important to note that in the above example, the shoulder reinforcement is cut on the partial bias, rather than true bias, with the run of the horse hair in the woof pointing upwards towards the shoulder point, to help push the shoulder point upwards, creating a higher, concave shoulder. True bias in the shoulder, with the hair in the woof pointing in the opposite direction towards the neckpoint is generally more typical of a less structured low shoulder.
Further layers of canvas may be used as an additional armscye reinforcement:
This is cut from body canvas in this case, but I have seen examples cut from chest canvas.
Finally, the bridle is reinforced with a strip of body canvas, such as on this example from Jefferyd
This helps to keep the front edge short and clean, throwing length to the armscye. However, an additional bridle of straight tape, line or lining is also used. Unstructured
The body canvas is cut out of a very soft linen-wool blend, cotton-wool blend or even pure linen. There are also some very light and soft camel hair canvasses available, or else cotton-camel hair blends that are suitable. The canvas may be cut on the bias to make it even softer and flexible, but this is not really necessary as modern canvasses are already soft enough as it is. However, Whife argues that the bias at the shoulder serves the additional purpose of having the canvas at the shoulder being able to naturally conform to the contours of chest and clavicle without recourse to cuts there to shape it:
Note how the canvas is on the bias at the shoulder (3), gorge (6), and scye (8 ). Whife states that:"it will allow shoulder shaping to be achieved without the insertion of puffs or the cutting out of slits".
Whife even argues that the chest canvas be cut on the bias:
The chest piece looks like this:
This consists of (A) felt and (B) chest canvas on the bias . Although Whife is silent on this issue, the horse hair in the woof likely points in the direction of the neckpoint, rather than at the shoulder point, as the latter will tend to push the shoulder point upwards in the manner of a structured concave shoulder, whereas an unstructured coat usually has a low shoulder. Note in particular, how extremely short the chest canvas is - it barely reaches below the level of the armscye.
Because of the bias cut canvas, only the barest minimum of canvas cuts are used. The first is made at the shoulder and gussetted open:
The second is at the armscye:
Here is a real life example of such a short chest piece (it hardly extends below the armscye on the right):
Note additionally the way it is cut away from the front of armscye, which mainly serves to create softness and ease at the front armscye. For some peculiar reason the hair cloth is cut on the straight, something that might be expected to interfere with the contouring of the canvas at the shoulder, thus necessitating additional shaping with extra cuts and layers. If the chest canvas were cut on the bias it might have further eliminated the need to cut away the canvas at the front of armscye.
The density of the pad stitches is kept low. Here is an extreme example:
Note too the avoidance of any domette or heavy felt on the chest piece, as this adds to the weight and structure of the chest. Instead a lighter material is substituted.
The number of cuts are kept to a minimum. This is partly because the canvas is very light, and it will lose its spring and shape excessively by the addition of extra cuts, making many of the older canvas patterns in this thread unsuitable. It is also because the addition of extra layers of reinforcement to compensate for the cuts will add to the structure. Lastly, lots of cuts means lots of shaping that produces the cleanly sculpture look of classical tailoring, and this is avoided in preference for a easier look.
A shoulder reinforcement is usually absent. The canvas at the shoulder is already on the bias. If a shoulder reinforcement is added, it should be a light linen canvas or perhaps even silesia - and always cut to sit on the true bias along the shoulder.
Lastly, the placement of a strip of canvas along the bridle is usually avoided. Instead, only a stripe of lining cut on the straight should be used for the bridle. Intermediate
Most real world canvas will show a mixture of the two approaches.
The chest canvas may be cut with the straight grain running parallel to the bridle, as on this example from Czujewicz:
The end result is that the chest canvas sits slightly on the bias, which lightly softens the spring of the horsehair in the woof. This is also more economical and wastes less haircloth.
The following example from Cabrera
is an example of a intermediate type of tailored chest piece:
Note the way there is a lot of rounding of the lower front edge, and it is so short that it hardly covers the front dart at all, but still longer than the true unstructured canvas from Whife. The idea is to create a softer roll at the bottom of the lapel.
In this example from Leibold, 1958, the chest piece is so short that it is does not cover the front dart at all, and the lower front edge is similarly blunted:
The density of the pad stitches is moderate.
Here is another example from Henry Poole (dissection on Jefferyd's blog
Note that the canvas is made of linen, yet the chest piece extends the length of the bridle.
The shoulder reinforcement may be cut from wool-hair body canvas rather than chest canvas or linen canvas. Otherwise it may be made of softer material such as linen canvas, or light body canvas.
The bridle may or may not have a strip of canvas reinforcing it. In many case, the reinforcement may be of something lighter than body canvas, such as linen. In the case of the above Henry Poole coat, removal of the layer of domette on the chest reveals the absence of a strip of lining along the bridle:
Note, however, the presence of armscye reinforcement - of linen rather than of chest or body canvas.