Hello Reza and team and forum members :) ,
First of all, thank you for taking the time to read my questions — and more importantly, thank you, Reza and team for the incredible work you do! I watch every video and truly appreciate the depth of your explanations. You’ve helped me move beyond simply copying old pattern drafts — now I understand why certain things are done, which makes it possible to make purposeful adjustments instead of relying on trial and error.
My main concern is the placement of the back seam, particularly in relation to how different drafting systems approach it.
I've noticed two distinct methods in historical drafting manuals:
1. Back seam is perpendicular to the chest line; Suppression begins below the chest line
That makes perfect sense to me: it maintains the clean perpendicular line across the upper back and places the shaping where it's needed: below the chestline. (I also understand that the center back seam should generally remain as straight as possible, since excessive roundness can create a bump. After all, the back is mostly a flat surface, only appearing concave from the side view — unlike, say, a camel’s back. Of course, in a three-seam back, we can’t rely on a ‘patrol back’ to do the shaping, so we have to work with what we have)
2. Suppression starts with an angled back seam right from the chest level down, which weirdly results in more aesthetically pleasing shapes, at least to my eye — especially those reminiscent of Edwardian silhouettes. However, I struggle to understand the mechanics here.
Wouldn’t sewing that just result in a tilted chest line? Fabric doesn’t automatically "know" where we "constructed" the chest line, right?
So wouldn’t this method:
· Lower the actual chest line,
· Increase the upper back balance,
· Steepen the waist angle,
· Potentially create a “duck bum”,
· And make the shoulder line appear more sloped?
As demonstrated in the illustration below?
So my questions are:
Why constructing the back seam at an angle in the first place?
And if we want to have a more fitted back in the waist with this method, do we just make the back seam more angled while maintaining it straight or do we just have to take in something from below the chest line and create some roundness?
Thank you again for everything you share. I’m learning so much thanks to your work!
Warm regards,
Luciano
Luciano,
First of all, congratulations on your very well formulated question with background info about the subject. EXCELLENT.
Now to answer your question: 1. The center back seam should never be drawn as your blue lined example. It will always be square to the back neck at the upper part before going into an angle towards the waist. When a center back is heavily suppressed at the waist, this kind of angle becomes inevitable. And yes it will result in a tilted chest line. 2. This kind of tilted chest line would not be a problem if it isn't your priority to have a perfectly horizontal chest line across the back panel. I can imagine this could be a priority when working with checks. Even then, most of the time, some tilt is perfectly acceptable. From a purely technical perspective, the position of a dart and its severity should be prioritised above pattern matching; the correct dart accurately shapes the cloth in the right areas and will naturally have consequences on the pattern design. Sacrificing the shape for the pattern design should be a conscious choice, knowing that it could compromise the shape of the garment and therefore the fit.
3. The change in the shoulder angle might seem to be happening but is not a reality. On a flat table with a flat pattern, yes, this seems to be happening. But in reality, the back hangs from the shoulders and the center back suppression really affects the hang of the lower part of the back; namely that the center back will move forwards like a forwards hip would do. The shoulders remain where they are. Just make a paper sample of a back with heavy suppression on the center back seam and make it stand up. You will see that the hip is position forwards in relation to the upper back. The shoulder will remain unchanged.
4. The first draft where the center back seam is perpendicular to the chest line is not accurate, for it seems to come to a sharp point right at the chest line. A sophisticated cutter would soften this line which will bring us to a line looking closer to the second draft which you included.
5. The suppression on the center back might affect the balance of the coat; the more severe it is, the shorter the back balance. Why? Very difficult to explain and understand; suppressed lines are concave lines, and concave lines on the edge of the fabric must be brought to the surface through an edge to surface transfer*. Why? Because the surface follows the shape dictated by the edge ONLY if the length of the suppressed line has been transferred to the surface. Otherwise the surface of the fabric will remain flat (a straight line) while the edge where the suppression is wants to be a hollow (a curved line). This discrepancy between the two results in a tension that will simply pull the cloth upwards which will give the appearance of a short balance. Yeah I know, sorry. Without an animation, I can't visualise this any clearer at the moment. 6. The right way to create a fitted back is by having some suppression on the center back, but taking the majority from the side seams. Of course there should be a balance between the two and it must be done in harmony with the figure of the individual.
Edge to fold transfer:
https://www.youtube.com/watch?v=1RIHknABXPg
I hope I have given enough pointers and a more thorough answer to your questions. I highly recommend doing the exercises in Lesson 14. You would ignore them at your own peril: https://www.youtube.com/watch?v=V6k6DLO0DGw&t=1230s
Reza
International School of Tailoring