A few questions regarding drafting and construction of trousers

[TTailor]

Im doing my best to learn everything I can about drafts, and I hope asking more questions is not a bother to those in this forum.

Duffy actually put his trouser draft on his website a few days ago, and looking at his draft answers, or at least gives me some good info on the questions I had. He has an interesting way of calculating the seat angle based on the drop. I wonder where that method originated. He finds the knee by adding 1.5" to 2" to the finished hem width.

For his draft, he adds the seam allowances to the inside leg on the backpart. Does this have an advantage over evenly distributing them to both sides of the backpart, like in modern drafts? Another detail I have seen is that the center line of his draft is actually 1/24 scale towards the outseam. His front crotch line measurement (horizontal measurement at crotch line) is 2/3 scale, like in many drafts, but other drafts often use the 1/3 scale as the crease line, which is further inwards than Duffy's draft. Why would Duffy bring this line outwards, when according to many old drafts, a line further inwards will give a cleaner look? Maybe he prefers a little more comfort in his trousers? He also uses 3" of ease at hip, compared to the 2" I have seen on many before, so maybe he really prioritizes comfort? As a note, he uses 3/8" for seam allowances rather than the standard 1/4", so that may change things a small bit.

Here is a link to the drafts on Duffy's website: https://www.handcrafttailor.com/notes-for-video-series

Please feel free to ask all the questions you like!

It was interesting to see his trouser draft. The way the draft is set up is less common nowadays.
I might draft it up along with my own draft to see how they compare.
Just glancing at it, i find the backs to look rather large, perhaps that is the ease or perhaps
I am more used to making period trousers which come up to the natural waist.

I use proportional formula drafting quite a lot in my practice, as i often have to produce patterns without the luxury of full, or recent or adequate measurements.🤪
Some proportional measurements are better than others. I admit to being a bit of a magpie in that way, using and applying a variety of sources to get to the end result.

[Gerry]

Some proportional measurements are better than others. I admit to being a bit of a magpie in that way, using and applying a variety of sources to get to the end result.

Snap! I've also acquired a handful of formulas, which are really useful as a guide/safeguard, even when I take comprehensive measurements. If things don't tally, chances are I've taken my measurements wrongly.

Some of the formulas in Stone's book on trousers (free download at internet archive) are remarkably accurate, at least in my case. He even has a measurement for inside leg based on height, which is as good as spot on for me! Totally useless in practice (who's going to measure someone for height?!), but amazing nonetheless.

[TTailor]

Take a look at this guy's cutting method

Ok that was painful to watch. Sorry I am feeling very opinionated these days. (maybe even cranky! Don't press my starteur! as we like to say jokingly)

He just uses a random 2 1/2 inch fork extension front and back. He didn't show any allowance for ease when he measures his back hip and with a low rise trouser and a waist to hip 33 1/2 waist to  42 hip he doesn't think that maybe a two dart back is required?

Does he actually have a video of the fitting of these trousers. I'd like to see how they turned out.

[TTailor]

He even has a measurement for inside leg based on height, which is as good as spot on for me! Totally useless in practice (who's going to measure someone for height?!), but amazing nonetheless.

We take height all the time, and sometimes that is one of the major measurements to work from. Even though I know some people fudge their height.
i find using height is surprisingly accurate. Inseam to floor 1/2 height minus 5 cm is almost always correct. Minus another 5cm for a trouser inseam also is a good starting place especially if you have not taken the measurements yourself.

[Gerry]

He even has a measurement for inside leg based on height, which is as good as spot on for me! Totally useless in practice (who's going to measure someone for height?!), but amazing nonetheless.

We take height all the time, and sometimes that is one of the major measurements to work from. Even though I know some people fudge their height.
i find using height is surprisingly accurate. Inseam to floor 1/2 height minus 5 cm is almost always correct. Minus another 5cm for a trouser inseam also is a good starting place especially if you have not taken the measurements yourself.

I stand corrected! (no pun intended) 

[Gerry]

Take a look at this guy's cutting method

Ok that was painful to watch. Sorry I am feeling very opinionated these days. (maybe even cranky! Don't press my starteur! as we like to say jokingly)

He just uses a random 2 1/2 inch fork extension front and back. He didn't show any allowance for ease when he measures his back hip and with a low rise trouser and a waist to hip 33 1/2 waist to  42 hip he doesn't think that maybe a two dart back is required?

Does he actually have a video of the fitting of these trousers. I'd like to see how they turned out.

Yes, when I first watched this there were certain things that I found baffling and that seemed to be needlessly creating problems. I could say that of so many tailor's vids I've watched, though. I suppose they sort everything out in fittings?

I mainly linked to his vids to show the 4 seams method. Which I seem to recall was mentioned in the Poulin book that I ended up looking through the other day. Perhaps this is where the method originates? Loads of Nigerian tailors use it.

[TTailor]

I mainly linked to his vids to show the 4 seams method. Which I seem to recall was mentioned in the Poulin book that I ended up looking through the other day.

Yes, I understood what you were trying to show.
I just watched the whole thing out of curiosity. Sigh.

[Gerry]

Just checked Poulin:

"Seam allowances are provided in the back part"

His measurements for knee and hem on the underside are 1" out from the topside, on the inseam. So presumably he used a 1/4" seam allowance ... unless I'm reading too much into his comment/method.

[TTailor]

I think you are correct about the poulin 1/4" SA

[TTailor]

I suppose they sort everything out in fittings?

I guess thats why they cost so much!!!!

[DOG SALT]

Thanks for all the info on how you take measurements, Gerry. Really great stuff to know. I also chose to measure my knee depth, as I find it is always a bit off. When the hip measurement is too high, is that using 1/6 scale up from the crotch to find the hip line? I know Stone's method uses 1/8 scale. Maybe stone is more accurate, maybe a direct measure best. When you say you move the waistline towards the hip to give a straighter outseam, are you using 1/4 waist, and moving that outwards, meaning there would be an angle to the center front? Or do you draft the fronts, and add enough towards the right to straighten out the outseam, so the fronts will be greater that 1/4 waist? How much do you usually add there? In this draft from Duffy, he says "I have chosen the 'straight leg' draft. Straight legs are characterised as having a two to three finger spacing between the knees when the legs are closed and the heels touch." I may just use the standard 1/3 scale for the centerline, as my knees are closer than this when standing as described.

Terri, I like what you said about that video. I'm sure there is some good info there, but I don't know if I can trust someone who uses the same  measurement for the front fork in all sizes. Maybe womenswear would be a good thing for me to study if I want to avoid people who do things like that... I wanted to ask a clarifying question about the waistband question I had earlier. With slant pockets, does pretty much everyone always press both seams upwards, even bespoke tailors?

So, adding the seams to the inseam of the backside does a few things. Allows better pattern matching, and removes the need to mark allowances. How does it affect the fit though? How would it compare to adding half of that allowance to both sides like in modern drafts? Am I wrong to say this is a modern draft thing? I believe in Aldrich's book, and a few other newer ones, they add the allowance to both sides, not all on the inseam. Really I am asking all these questions to understand how to get the best fit out of a pair of trousers. My thought is that if old bespoke tailors add all the seams to the inseam, maybe it fits better than modern methods? Especially if Duffy uses it, I would think there is something to it. Maybe I'm wrong though, as obviously many old drafts use methods we have greatly improved upon.

Another thing I've been thinking a lot about is darts in the backs of trousers. Most of the time what I've seen in drafts is they square from the waist down, that line being the center of the dart, and then draw the legs in on both sides of this line. When sewn, this dart will distort the waist line. It will make the 180 degree angle now bow inwards. Wouldn't ideally the waist seam be straight, or does this amount not really affect the finished product that much? Thinking in the 3D, wouldn't it make sense to add a bit of length to the legs of the darts above the waist line? This would add length to go over the hip, and would allow the waist line to be more of a straight line when sewn. Am I over thinking this?

[Gerry]

When the hip measurement is too high, is that using 1/6 scale up from the crotch to find the hip line? I know Stone's method uses 1/8 scale. Maybe stone is more accurate, maybe a direct measure best.

Yes, that's pretty much it. 1/6 positions it too high. Not by much, but it does make a difference. The estimate of 1/16th seat (1/8th scale) is spot on for me and corresponds with my measurement. Like I said earlier, I use it as a safety check, to make sure I'm in the right ball park.

When you say you move the waistline towards the hip to give a straighter outseam, are you using 1/4 waist, and moving that outwards, meaning there would be an angle to the center front?

Yes, that's exactly what I meant. Whether you need to do this depends on body shape, of course.

Maybe womenswear would be a good thing for me to study if I want to avoid people who do things like that

I know this question wasn't directed at me, but I actually started with a book angled more towards women's wear (though it covers men's too)."How to make sewing patterns" by Donald H. McCunn. The approach is very intuitive and has enabled me to understand other methods, despite many of these being cloaked in alchemic fractions which cutters seem to delight in. The downside of the book is that: it misses many of the tricks that tailors use; ridiculous amounts of ease are added here, there and everywhere; the pivot method doesn't create a great cut for me; plus the leg placement (with my measurements) is not centred, and creates the 'women's pants' look that I mentioned earlier. Despite all this, it's definitely worth glancing at.

So, adding the seams to the inseam of the backside does a few things. Allows better pattern matching, and removes the need to mark allowances. How does it affect the fit though?

That's something that you'll have to evaluate yourself, really. In my case, it works out fine. Plus it depends on what method you use in general. When it comes to the underside, it's like the Wild West out there. Everyone has their own way of doing it. Which is very confusing when starting out (that's certainly what I experienced).

Another thing I've been thinking a lot about is darts in the backs of trousers. Most of the time what I've seen in drafts is they square from the waist down, that line being the center of the dart.

Ideally, the dart(s) would be pinned and shaped in a fitting, like they do in women's couture (that's the approach in the book I mentioned). Most tailors seem to go ahead and sew them in, regardless.

You have to think about what the dart is doing. If there's no shaping at the outside seam of the underside, then a dart/darts should be used to create some. In my case, I do incorporate shaping, so I only need a single dart to shape over the backside. This is placed in the middle of the waist (on the quarter) and angled towards the mid-point between the underside fork's tip and the outside seam at crotch level - which should be where the fullest part of the buttock is. It's a trick I picked up from an old 1950s pattern. It works really well ... at least for me (there are no hard-and-fast rules, it seems).

BTW, you're not overthinking it. Without questioning, there's no progress. And every cutting method I've come across (including the one I use) is a compromise. We're all working towards a better cut ... at least I hope that's the case!

[TTailor]

So, adding the seams to the inseam of the backside does a few things. Allows better pattern matching, and removes the need to mark allowances. How does it affect the fit though?

It is merely an alternative drafting process.
If you followed that protocol then shifted the back panel laterally so that it is similar to a draft that applies measurements equally on either side of the front panel, you can compare the shapes, and they are probably quite similar.
Adding all the seam allowance values for both the back and front onto just the back panel results in a more narrow front panel.
that may be desirable or not, depends on what you like.

Regarding marking allowances, there is seam allowance on the fronts, and you would cut on the drawn line and sew 1 cm in from the line. On the backs, it is usual to leave inlays so you would mark the chalked pattern outline with tailor tacks. When you sew the seams, you lay the front panel on the back matching the cut edge  of the front with the chalked line of the back and sew 1cm seam allowance ( or 1/4" old school) if you don't leave inlays then you would just match the cut edge of the fronts and backs and sew at your specified seam allowance.

Back darts- yes, you can and should fold them out in the pattern and correct the run of the line. standard operating procedure. If you don't do that you will correct it while sewing. After the darts are sewn, you will mark a better waistline. Either way, you need a nice line to follow.

[Gerry]

      The seat angle is something I have been thinking about. Most methods I have seen for finding this just use a proportional method. Often I have seen they rule a line from 1/2 the distance of the front fork extension (1/12 scale from the center front) to a point 1/6 scale + 1 inch or so up the center front line from the crotch line. I have read that taking a direct measure is a better method, and I was wondering how one would take that and apply it. How would this measure be applied to these points? Do we use the point 1/6 scale + 1" up, and pivot there, or pivot from the point 1/12 scale from the CF? Or do we use completely different points for this?

I recently discovered a clever way of measuring the rise (and therefore seat angle) needed at the back of trousers. Basically, thread some string/a boot lace/ some bias tape through the hole in the end of a tape measure, and tie it round the top of the thigh. At the back of the body, measure up to the waist line you desire for the garment and, keeping the measure in place, gradually sit, allowing the measure to lengthen as the backside muscles expand.

Whatever the difference is between the two measurements is the amount of rise needed at the back. You would then measure this amount above the seat line (at the centre back line), in order to pivot your pattern accordingly. Or pivot up from the waistline's side seam to a 'rise line' that corresponds to the measurement taken. Basically, adjust it to whatever cutting method you end up using.

In my case, the difference is exactly 2", which is what I've been using for my drafts through trial and error.

If you scroll down to the heading "How to Make a Pants Sloper" and click on it in the link below, it will take you to the "An Introduction" video. It's around the 2:45 mark in the vid (a rough-and-ready intro to his cutting method, which isn't as ramshackle as this in reality):

https://patternmaking-classes.com

[DOG SALT]

That is definitely an interesting way of finding that measure, Gerry. I think I saw that guy's videos a few years ago but his method seemed a little too strange for me to want to try. Now that I revisit it, there's probably a lot I could learn from it.