Well it completely baffles me why the waistline would be placed in one place then advice given to have most suppression at a point not on the natural waist (though I'm sure someone has a convoluted explanation - including pseudo geometry - as to why).
That amounts to an irresistable challenge
. I'm not privy to the details of the Kim & Kim book, but I'll venture a go. My "convoluted explanation" will thus be based on the little information I have as well as some guesswork.
For the construction of the slopers (I shall use that American term, the authors give a reasonable explanation for it) the authors place the waist line at a distance of
back waist length from the reference point. I suspect however, that they measure the
back waist length of the figure not vertically, but following the body contour. That introduces a difference.
If I take as an example what they show on page 33, where they transform the
Close-Fit sloper into one with waist darts, they first raise the waistline by ½" and then take out a total of 2", divided between 2 darts and the side seam on that new waistline. I assume that they realise that the waistline of the figure lies higher than the waist construction line of the sloper. Where the waistline exactly is, is insignificant until waist shaping is introduced, as the sloper describes just a straight tube.
Now for the "pseudo geometry" bit, which should show us if this is a reasonable supposition.
Let's assume we have a figure of regular type with a chest measurement of 40", what they call in the book
40R. According to the table the
back waist length is then 18¼". I'm unsure if there is any ease incorporated in this; let's assume there isn't. The measurement will begin at the reference point, follow the natural curves of the spine, and end at the waist. The sloper however will be drafted with the measurement straight down. If, for an approximation, we use the image in the book with the usual neck and waist indentations, the curved line ends up at a height of about 95% of the straight line. For a length of 18¼" this means a bit more than ¾" higher, which does seem to be in the ballpark.
Perhaps this somehow satisfies the "convoluted explanation - including pseudo geometry" criterion, but if not, I'll look forward to what a successor has to say about it.
On the present issue of obtaining a shirt pattern. Is it really thought that this design is suitable for this particular figure? If I remember correctly, it was proposed in reaction to David Coffin's suggestion to a poster in the other place who wanted to make tight-fitting shirts for body builder types to use princess seams. For those mushroom-shaped figures with well-developed shoulders and chests and small, trim waists the design seems suitable. They didn't come back for further discussion however; what would have been interesting as well was how to handle the apparent balance problems, probably resulting from removing too much width.
I have no clear picture of what the objective here is I'm afraid. Is it just an exercise in handling waist suppression? An exploration of how to divert attention to the chest region? And what exactly is a "dress shirt" in this context, is it a garment for formal (evening) wear? In the latter case I would not use this design. If it is about buffing up the upper area, I would try to extend the shoulders outward as far as possible, perhaps even use epaulettes, or saddle sleeves or similar, and would keep the chest roomy (I find the front chest too narrow here, and there seems to be tightness over the right shoulder).
In this particular figure the waist could then be narrowed in back and side, but I would hesitate to take anything out in front. Other options would be to use a large front yoke, or some plastron-type design, or a limited length opening with broad elements, pockets; the possibilities are endless really.
I further notice that it has been decided to keep the current front/back imbalance, as well as the deviating centre back. One has to be aware though that if striped or chequered fabric is used, those lines are likely to be emphasised.
On another note, I'm afraid I have to respectfully disagree with the Experienced Professionals if I understand correctly what has been said upthread. It's more important that the darts follow the general and apparent shape of the body than that they are "vertical". In fact, the darts themselves aren't vertical anyway if they are plotted with their centre lines vertical. The most vertical you can get is to make one leg of a dart lie on the straight grain. The other leg will then be off-grain if the dart doesn't include an angle of n × 90°. In this back I see the centre back line consistently deviating to the right, and I assume it is on the lengthwise grain. This arrangement has obviously been chosen, even if it implies that the hang of the back is not following the grain accurately. The back waist suppression darts should then, when sewn up, appear symmetrical with respect to this line. If angled, i.e. off-grain darts pose a problem, depending on the fabric, they can be stabilised, and in fact the stitching itself provides some stabilisation. Nobody bats an eyelash about a very slanted bust dart in a dress anyway, or extended dart rotations to unusual positions. Moving the direction of the darts away from the centre back line will present ugly distortions in striped fabrics.
One other thing about those two-pointed waist darts, if used as darts opposed to being incorporated in seams. During fitting, it's perfectly fine to pin the amount to be taken out outwards. When the darts are sewn closed however, the folded seam allowance in the centre will be the shortest length, shorter than the total length of the dart. Especially in the waist region this can prevent the dart to occupy its real position. With larger darts and unstretchable fabrics this may necessitate cutting the dart open and stretching the seam allowances.
