Seam allowances for darts of T&C system

[OlymposPartizanos]

I raised this question earlier because what I've use for drafting and construction for jackets before is starting without seam allowances, and with a side piece. I'm trying something new to make a jacket without a side piece according to some T&C drafts before 1950s, and confused by how much I should actually sew for darts according to those old drafts.

Here's the earlier post: https://movsd.com/BespokeCutter/index.php?topic=1383.0

I did a few hours of reasearch today. The final answer is, interestingly, it seems that does't have a strict answer for this. It might really depends on the style you want during construction...

Here's what I found out:

First start with the 1928? edition of MTOC:





It is quite clear that 2 seam allowances are taken from the bottom of scye, down to the under arm dart . The front dart just sew right on the mark, althoug it is only a 1/4 inch dart according to instruction.

More proofs of seam allowances taken from scye bottom to under arm dart in a picture in its coat making instructions.

[OlymposPartizanos]

However, I've find something more from the old Cutter & Tailor forum:

https://web.archive.org/web/20130310234436/http://www.cutterandtailor.com/forum/index.php?showtopic=949

By Sator:

"I have just noticed that this draft is rather unclear as to how much waist suppression should be added at the front and side seams.

This is what A.A. Whife had to say in the 1960s:



This should give a rough idea of how much waist suppression is reasonable through the front dart, and underarm seam.

Notice that Whife usually will have a seam allowance on his darts. That is a 1/4" front dart will become enlarged into a 3/4" front dart once sewn up with 1/4" seam allowance. This is in contrast to the Rundschau way of doing things where the darts are sew exactly on the chalk marks on the cloth. That is, the darts are not enlarged when sewing them up."

The under arm dart seam allowance is the same. But the front dart now is different, which means many of the T&C system drafts have front darts sewn out 3/4 inch when stating 1/4 inch in instructions.

But if applying this to the 1949 edition of MTOC, front dart that "is suppressed 1/2 inch" would turns into sewing 1 inch for front dart. I really doubt that it should be such a large amount...




And one of a 1937 T&C draft uses 3/4 inch front dart, which means 1 1/4 inch if applying this instruction. It sounds to be too much...

[OlymposPartizanos]

What's more:

Here's something from the jacket construction part of MTOC (1949 ed):




Which means now you don't need to sew the double seam allowances at the bottom of the scye, which is, again, contrast with the 1928? edition. Though I think you still need to sew 2 seam allowances more than the draft in the under arm dart at waist.



I think the answer now is more clear: The only thing is sure for the T&C system draft is that 2 seam allowances needs to be added to the underarm dart at waist. Whether sewing 2 seam allowances more at scye bottom or front dart is really decided by the style wanted and at trying on.