Trouser drafting/fitting

Started by nailclipper, September 08, 2023, 12:24:57 PM

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nailclipper

Hey guys, have a couple of questions!


1. Can the back waistline be curved? (attached pic)
   Any issues if so?

Seat seam will be reduced by x, side seam to reduced seat seam curved.

Been researching how to reduce back trouser balance. Tried a few methods and didn't like them (straightening back seat seam but just gives a wedgie, hip and etc).






2. Drafting front side seam and inseam unequally in width.

Understand to get the centre crease line, most tailors line up the side and front seam and press.

If both are unequal, wouldn't the centre front crease be shifted? Any issues?




posaune

I have only my Little Tablet to Look at your drawings. I think this draft -the back Part - is very ,,inward" drafted. The centerline does Not run through Center Knee, only through Center hem. In my drafting System Recentering the back Starts at hip Level. (You lay the Center maybe 2 cm to the Right) And you can Choose how much you Want it. The Knees Are centered Front and back. The Last Part of the inside seam will mostly have a  Bit More fabric. It depends on crotch width and thighs. As the Front Crease line is Grainline  - no shifting.
Lg Posaune

Gerry

1. Your curve for the waistline is the mirror image of what it needs to be. At present it's concave, it should to be convex (unless you want a pronounced point at the CB).

Allow inlay for the waist, fold it over and sort out the waistline during a fitting. Then chalk along it for transferal to your pattern.

2. Having determined the correct crease line (see below), stick to it: baste it and press along it (regardless of asymmetry).

In theory, one can find the crease-line by determining the centre point between fork and side seam. And many tailors use this method (as did I in the past). However, it's flawed. The tip of the fork doesn't lie at the side of the inside leg. In reality it's pulled into the gap between the legs, in order to bridge it. So the actual centre-point is slightly more towards the side seam, not at the mid point.

Mostly, you don't notice because cloth has drape, collapses around the leg and all looks fine. However, when I made some trousers from cotton drill the legs were like cardboard tubes before pressing, and the outer parts of said tubes banged against my thighs. The leg position was off slightly for the reasons given above.

How to determine correct crease/leg centre line? There are estimates (can't remember them off the top of my head, but I'm sure you can find them). Personally, I simply drop a tape measure vertically down from just above the top of the leg so that it aligns with its centre. Mark this upper point (pin/chalk whatever trousers you're wearing) and measure across to the fly-line. This is how far you need to come out from centre front/fly-line to determine each leg's correct centre position. This assumes a relatively straight-leg posture, however.

As mentioned above, baste this line on your cloth and stick to it when pressing (any asymmetry doesn't matter).


nailclipper

@posaune

My bad, didn't clarify. The pictures were found online and just used as examples. I'm using the Mueller draft.


@Gerry

Right, the crease line is not exactly in the mid point.


"Your curve for the waistline... At present it's concave, it should to be convex"

- I've attached my back pattern showing my earlier point of it curving in, or convex.
- Is this fine? Nearly all drafts from researching have a straight back waistline.
-(Ignore the other lines, trying to find ways to reduce the back balance line without affecting other points.)

Gerry

Quote from: nailclipper on September 10, 2023, 03:08:36 PM@Gerry

Right, the crease line is not exactly in the mid point.

I've attached my back pattern showing my earlier point of it curving in, or convex.
- Is this fine? Nearly all drafts from researching have a straight back waistline.


What you've drawn is concave ('caving-in'), not convex. Yes, many drafts just show a straight line. In reality, especially with lower-rise trousers, there'll be a slight, convex bow to the waist in the back panels, and a slight, concave scoop in the fronts. This is less pronounced with waisted trousers, but either way renders a smoother transition at the side seams and coverage of the seat at the back (more critical with lower-rise trousers).

None of this is crucial when drafting so long as you leave inlay at the waistline. Hence the straight lines shown in many drafting systems. The actual shape/line gets sorted out in a fitting and will be transferred to the draft for future pairs of trousers.

If you're trying to predict that curvature/line exactly in a draft, you're on a hiding to nothing (in my experience). However, you'll get closer by not scooping the back out as per your draft. The way you've drawn things, you'll have a slight point at the CB: think about the mirror image at the CB seam; better yet, draw the mirror image on a bit of scrap. You may also have slight points at the side seams - a fitting would say for sure, but you can also but your front and back patterns up against each other at the side seams to get an idea.

nailclipper

Quote from: Gerry on September 10, 2023, 08:03:47 PM. The way you've drawn things, you'll have a slight point at the CB

By slight point, do you mean when sewn up, it doesn't fit nicely/pucker? Don't know the term for it.

At CB seam, I drew a 90º angle of about 1", curved to side seam. Side seam isn't 90º. I should change it.

I'm trying to reduce the back balance without changing the seat seam angle (or any other parts), and other alterations i've researched. Those just give me a wedgie.


Attached front trouser waistline. Side seam/fly line drawn roughly 90º.

Appreciate your help greatly, Gerry. Thank you.




Gerry

#6
You're literally creating scoops at the back, between the CB and side seams. This is going to result in slight 'peaks' at the CB and side-seams if you're not careful. The waistline should be continuous and smooth, not something with obvious highs and lows.

To understand what I'm getting at, take your back pattern and on some scrap paper draw around it, from the top of the CB seam going into (and a fair way along) the waistline. Flip the pattern, align its CB with the CB line you just made and draw round it again, to mirror what you just did. What does it look like? Can you imagine a straight waistband being sewn to it?

Gerry

Both of these diagrams are exaggerated, but the top is how I would balance a waistline. Below is what you've done.

https://flic.kr/p/2p28gzP

In reality, these curves are more subtle, particularly with waisted trousers.

TSjursen

The shape of the top of the trouser is a minor thing, you will figure that out when sewing it up or in a fitting.

You say you want to reduce the balance without changing the seat seam angle. Can you try to explain what you want to achieve by doing this? Ie how does the trouser look now and how do you want it to look when the alteration has been made?

Greger

Seems like you have been looking in the wrong places to get directions for making patterns.
This place has better advice. Poulin has a trouser pattern and a few directions for fitting. That's just one set of directions you can find here. Some Cutter and Tailor are to be found here. German one's.
The curves for the waistband to be sewn on has to be straight and level. Darts add curves. The cloth may, or will be, pulled up to fit over the curves of the body. Some of this is fine tuned during the fittings. Also, is the back fork to long or, short? Are your curves to deep? Front and back? You can always trim away excess. But you can't add to it. When designing style or fashion (nothing wrong with style or fashion, it depends on why you are wearing them) add inlays for them to fine tune their appearance. To do this proper know why the style or fashion exist so that you are working towards more than appearance. You want the person to fit into the style or fashion.

nailclipper

Quote from: Gerry on September 11, 2023, 01:10:12 AMtop is how I would balance a waistline.

When balancing waistline, do you place the
1. Front and back knee together or
2. Top of side seams

1

2


1. Seems to be more logical for me

nailclipper

Quote from: TSjursen on September 11, 2023, 05:36:20 AMThe shape of the top of the trouser is a minor thing, you will figure that out when sewing it up or in a fitting.

You say you want to reduce the balance without changing the seat seam angle. Can you try to explain what you want to achieve by doing this? Ie how does the trouser look now and how do you want it to look when the alteration has been made?

Have tried quite a few methods, but most seem to give a wedgie/reduce comfort. Would like to retain as much comfort in the back seat while looking as clean as possible.



Having done many fittings, I now realise its impossible and not ideal to have a 100% clean fit (comfort). Posture gets really bad when legs are tired etc...

Gerry's post gave me an idea and a good compromise so far.

nailclipper

Quote from: Greger on September 11, 2023, 10:24:21 AMSeems like you have been looking in the wrong places to get directions for making patterns.
This place has better advice. Poulin has a trouser pattern and a few directions for fitting. That's just one set of directions you can find here. Some Cutter and Tailor are to be found here. German one's.
The curves for the waistband to be sewn on has to be straight and level. Darts add curves. The cloth may, or will be, pulled up to fit over the curves of the body. Some of this is fine tuned during the fittings. Also, is the back fork to long or, short? Are your curves to deep? Front and back?

Back fork too long. Back curve is 1 1/4" at a 45º angle. I find this to be a good height/length for the curve.

Thanks for the Poulin recommendation, forgot I had it. Method is really decent.

Yeah sewing up a baste with the waistline being curved made it troublesome.

I have tried almost all the alterations I could find, the most recent one was an adaptation of the fish eye dart. The best "fish eye dart" alteration would be from Mueller. But altering, looking at it and sewing a baste felt weird.

But the Mueller alteration changes a few stuff that seemed unnecessary and not ideal for me.

Gerry

Quote from: nailclipper on September 14, 2023, 04:20:49 PM
Quote from: Gerry on September 11, 2023, 01:10:12 AMtop is how I would balance a waistline.

When balancing waistline, do you place the
1. Front and back knee together or
2. Top of side seams

1. Seems to be more logical for me

Because of the curvature of the side seams, and the darts at the back, butting the side seams together is not only difficult, but the waistline won't look exactly as I sketched things in my example. As I alluded to in my first post, and explicitly say in my second, "The actual shape/line gets sorted out in a fitting and will be transferred to the draft for future pairs of trousers."

Once you've done that a number of times, you'll get an idea of what you're looking for/at when drafting. Then you have the experience to draw in some rough, curved lines that will get you close to end result. And you'd butt the front and back patterns right at the top of the seam for about an inch, trying to keep both patterns on grain. But I can only stress again, it won't look exactly like my diagram (that's how things end up looking). It's just a momentary thing one does to check to see how the lines are running into each other. I only drew those lines to demonstrate that what you'd done was problematic. They weren't intended as an example of what to draft.

Equally, you could draw straight lines, as a number (including myself) have mentioned. To reiterate what I said in my first post:

"Allow inlay for the waist, fold it over and sort out the waistline during a fitting. Then chalk along it for transferal to your pattern."


Gerry

These are low-slung trousers - I have a 34" inside leg, so waisted trousers make me look like an ostrich. Hopefully you can see just how subtle the curves are. Less so on the front, in my case, because there's a scoop to undercut the belly (which looks more elegant with low rise IMO). This makes things noticeably concave (not that you can see it in the photo). Notice that you can barely see the curvature of the back; and the open darts - the CB seam is actually a dart too, right at the top, to help avoid gapping at the small of the back - make it look quite flat. It is slightly convex, however.

https://flic.kr/p/2p2UAW1

When striking the cloth, I also mark out material at the top of the darts to compensate for the angularity that closing them causes. As TSjursen mentioned, these details get sorted out when making the trousers.

PS That second photo of yours looks like a good fit. Don't forget that trousers settle in with wear, and become more comfortable.