Bespoke Cutter And Tailor

another vote for a bigger crotch diameter.
lg
posaune
Asymmetrie? Have you measured your left and right side and thighs? Right side looks better.
(With some figure types I measure the hip girth in a special way. But this is me:
In back I lay the band over the top of the gluteus maximus and then I move the front part of the band up and down to catch the belly and protruding thighs. And compare it with the horizontal measurement. After this I decide what to take.) 
I could not attch a pic, doing something wrong?

Thanks for the crotch diameter vote posaune! I am drafting a new pattern now, and would like to get something close to a fit without making too many more toiles (right, Gerry?).

I am looking through the Müller Trouser book and I see a few different formulas depending on the block. Most of them use 1/10 of 1/2 of the Hip Girth + 1 cm for the Front Crotch Width. Sometimes it is + 0.5 cm, but there is not much one can adjust there.

With the Back Crotch Width, it is calculated by subtracting the Front Trouser Crotch Width from the Total Crotch Width. The Total Crotch Width with this Skinny Fit trouser block is calculated as 1/4 HG - 4 cm. I have noticed though, that this formula changes depending on the type of trouser one is drafting. The Slim Fit Trousers on pg 9 specifies 1/4 HG - 3 to 4 cm. The calculation depending on the trouser is either a minus single number, or - 3 to 4cm, or - 4 to 5 cm.

As the Back Crotch Width is looking like the place where the crotch width is determined, and because the Total Crotch width is what determines that measurement, it might be that in order to change my crotch diameter, I will need to alter my formula.

What if I change the Total Crotch Width from 1/4 HG - 4 cm, to 1/4 HG - 3 cm? This would mean a new Total Crotch Width of 22 cm (previously 21 cm). If say the HG was 100 cm and 1/4 HG was 25 cm, then the Front Crotch Width would be 1/10 of 1/2 HG + 1 cm = 6 cm. Taking the Front Crotch Width away from the Total Crotch Width to get the Back Crotch Width gives me 16 cm... I gain an extra cm.

I am sure I could have summarised this a lot easier. Just thinking out loud. Is this something I should be trying now?

Please tell me if I have this wrong.

Crotch depth for front and back pieces can be expressed as a ratio. It's roughly 1:2 from front to back (the back is double the width of the front). Older type drafts can use something like fifths IIR (possibly 2:3 ratio??).

You could use your current widths to work out an approximate ratio, increase your crotch width a little and reapply said ratio to the new width. I didn't go through your calculations because metric doesn't register with me when it comes to tailoring, but it's simple enough to do.

It is actually possible to measure crotch width. There are a couple of ways of doing this, one an estimate the other exact. In the case of the latter, it's highly invasive and, with some people, wouldn't be that hygienic, so not something to be done, frankly. It's also difficult to do on yourself.

With the estimate, we improvise a calliper. Place a T-square between the legs and hook the T part onto the back of the legs at the crotch line, just below the seat. Slide a rule along the front until it butts up against the front of the legs at the crotch line and read off the depth. The actual depth we want is from the  coccyx to the pubic bone, but if you look at anatomical drawings in profile the top of the thighs at crotch level has a similar/the same depth.

This measurement often needs a little extra cloth, for the reason I gave earlier: the tips get pulled into the gap between the legs in order to bridge it. With most people this isn't a problem and what was measured will suffice, but with a prominent seat (not necessarily large, but muscular will do it - and that's my case) the backs fill up more than anticipated, creating a slight pull on the front fork. A tiny pull can twist the whole leg slightly inwards, causing off-centre creases. Very annoying to diagnose because often there are no obvious signs of stress at the front.

As for the exact method, it's very similar to the above, only the T-square is held vertically. The tip of one leg of the T is pulled into the crease of the backside so that it butts up against the coccyx. A ruler is then slid along the main length of the T (which protrudes from the front of the legs) until it butts up against the pubic bone and a measurement is taken.

The ruler has to be perpendicular to the floor and it's very easy to accidentally angle it when measuring oneself. Things like knicker-elastic can prevent the T-square from nestling between the crease of the backside too. Like I said, highly invasive and not worth pursuing IMO because the result (assuming you get a correct measurement) is often the same as the estimated measurement.

I would add 4cm to the hip measure for the new draft. Thus you have 1cm at each seam to remove from the hip bow.
I would take the pattern calculations, the increasing should also increase the crotch diameter.
Taking a measured crotch diameter for drafting was difficult for me.  I didn't know in which hight to measure and then where to apply it. Although it's most probably at hip line level. (the hip hight level itself is often just calculated instead of measured. Doesn't match the individual hip line hight necessarily)

Thanks peterle. My hip is 100 cm, so go up to 104 cm is what you are saying. Yes, the hip will increase the crotch diameter.

Front Trouser Width will be 26 cm
Total Crotch Width will be 1/4 HG - 4 cm = 22 cm
Front Trouser Crotch Width 1/10 of 1/2 HG + 1 cm = 6.2 cm
Back Trouser Crotch Width TCW - FTCW = 15.8 cm

Previously I had a Front Crotch of 6 cm and a Back Crotch of 15 cm. So I get an extra cm total. If I changed the TCW formula to 1/4 HG - 3 cm, I would get another cm in the back crotch.

I will draft a pattern on paper and see what it looks like.

I am actually a little worried about this. It might fix the crotch width issue, but cutting off the side seams 1 cm... would that not throw the crease lines into disarray?

Quote from: peterle on August 24, 2024, 12:28:37 AMTaking a measured crotch diameter for drafting was difficult for me.  I didn't know in which hight to measure and then where to apply it. Although it's most probably at hip line level. (the hip hight level itself is often just calculated instead of measured. Doesn't match the individual hip line hight necessarily)

Hopefully this diagram makes things clearer:

https://flic.kr/p/2qbC52r

The top, blue line is the actual measurement we'd like. The position of the coccyx is usually at the fullest part of the seat. Which makes sense, because it's a delicate bone and needs all that muscle bulk for protection. If someone has a flat backside, then the top of the pubic bone can be taken as the fullest part/seat-line. Either way, a simple drop of the tape measure to floor from the seat-line gives us our exact vertical position (estimates not required), at which we apply our measurement.

The estimated measurement is in red. It's taken right at the top of the leg, at the crotch line, with the T of the T-square horizontal (parallel with the floor). The 'legs' of the T hook onto the backs of the actual legs, right below the seat. Hopefully you can also see from the diagram that the distance is similar to the actual crotch width.

As with all measurements, there's always margin for error; and the body being what it is, drafts can create slight positional changes compared to the reality of things. I much prefer doing this than using estimates, though.

PS I roughly drew those lines on the diagram using paint, which was very fiddly. So the positions aren't ideal, but you get the idea ... 

PPS Just for comparison, Stone's estimate (IIR) is a sixth of seat for the total crotch width. With a 38 inch seat, that gives me 6.33 inches. My estimated measurement is 6 3/8ths and my actual crotch width measurement (wedging the T-square in my a*se-crack and saying three Hail Marys) is 6.5 inches. All work, though I need to add 3/4 inch in my case, to prevent crease misalignment at the knee (see earlier post).

Thanks Gerry. This is really useful information. I am drafting onto paper right now. I'll make some measurements and check I am in the right range with the pattern.

Don't change the formula alone, draw the pattern with the enlarged measurement. Don't forget, also the back seam position is calculated from the hip width. Thus back seam position and crotch diameter are linked. Changing just the crotch diameter will disturb the proportion of the draft.

Quote from: Trouser Snake on August 24, 2024, 12:46:36 AMI am actually a little worried about this. It might fix the crotch width issue, but cutting off the side seams 1 cm... would that not throw the crease lines into disarray?

No, I don't think so.
Draw and sew the trousers as usual (without removing the added amount) and pin it at the fitting if you are in doubt. Your front crease lines tend inwards slightly at the top anyway at the moment. Getting them a bit outwards wouldn't be bad.

Gerry, thanks for the sketch. I don't understand why it is measured just to the bone. I always thought the fleshy parts of the butt are also part of the body diameter that is to be covered. I would love to know the thoughts Mueller has regarding the crotch diameter. Sadly they hardly give a detailed insight to the reasons behind the pattern steps.

Quote from: peterle on August 24, 2024, 07:09:01 AMGerry, thanks for the sketch. I don't understand why it is measured just to the bone. I always thought the fleshy parts of the butt are also part of the body diameter that is to be covered.

The curve of the CB seam nestles in the crease of the backside, so crotch width is from the bone at the back (coccyx) to the top of the bone at the front (pubic), plus the relatively small amount of flesh covering them. The fleshy part of the seat is accommodated by the ease across the backs.

The estimated crotch width measurement is something I got from Don McCunn. IIR, he used a pair of L-squares to improvise a calliper, which seemed very convoluted to me. Besides, few are going to have more than one L-square. It's much easier to do with a T-square and ruler (or a single L-square and ruler, for that matter). The 'exact' measurement is of my own, perverse devising. It does work, but it's not for the faint-hearted.

I don't use McCunn's drafting method, incidentally, but I started with his book, which is a nice intuitive approach that takes some of the pseudoscience out of cutting (at no point do you ever find yourself saying, "why am I doing this?").

Quote from: peterle on August 24, 2024, 07:09:01 AMI would love to know the thoughts Mueller has regarding the crotch diameter. Sadly they hardly give a detailed insight to the reasons behind the pattern steps.

If my experience is anything to go by, I think most people try out various cutting systems till they find the one that works for them, then they swear by it. If a draft doesn't work for someone else, then clearly their body has 'anomalies' that require adjustments - the cutting system is never at fault in any way, of course!

Given that so many systems have different estimates for the front and back fork widths, they can't all be right. Which suggests that inseam placement isn't overly critical (there's a small margin for individual preference and/or error).

I watched a lecture online about body scanning sometime ago. It's clear that there are regional differences in body type around the globe. And body shapes and heights have changed throughout the ages, so estimates in books can be very hit or miss for the modern cutter. Scanning can provide exact measurements, however, including for crotch width, so things will undoubtedly get better in the future.

I have been drafting the pattern. Slowing down a bit the past couple of days.

I have used a Hip Girth of 104 cm and run exactly to the recipe in the book. I have drafted and cut out the trouser front paper pattern - looks good. I am currently drafting the back trouser outer leg seam. My waist measurement used is still 90 cm. The issue I am having with the back trouser is because I have increased the Hip Girth from 100 cm to 104 cm, where my outer curve meets the waistband from the seat line, that curve is quite accentuated. Before it was not so extreme. I think I am going to end up with a womans hip shape.

Should this be a concern for me at this point? I assume I will be reducing the measurement at the hip by 1 cm each side in order to fit these. The point of going up to 104 cm HG was to increase the crotch diameter. I should just soldier on, yeah?

The point was not just the larger crotch diameter but also to get everything at the right place. At the fronts there will be a little more room between crease an zip line. Same for the back, slightly different back seam position.
When you've finished the pattern you can also flatten the hip curve in the draft before beginning the toile.

Yes, I have already noticed with the fronts that the original calculation with the Front Trouser Width (1/4 HG - 1 cm), gives me 25 cm, which is what I was trying to achieve previously by dropping the - 1cm and just using 1/4 HG when it was 100 cm HG not 104 cm.

There is no ease on the waist band on this pattern, so that increased HG has to curve in more on the back to meet the 90 cm waist band. I am assuming to flatten the hip curve, I might be cutting into the hip line rather than adding to the top. I will cut this out with 3 or 3.5 cm allowance around the edges so I have ample room for alterations.

I have just realised... the ease or half ease is taken from the measurements of the hip line: subtract front from back. My front is 25 cm and the back is currently 27.5 cm, giving me 2.5 cm per half trouser. I will cut and sew the calico to the paper pattern. Perhaps the 27.5 cm of the back 1/4 HG where it meets that side seam is what will be adjusted?

I have hit a wall with this. Because of the increased HG, the waist measurement of the front has increased. This means that the backs are now smaller at the waist line than the fronts.

I am now thinking that the front pattern will have to be trimmed down at the hip line and waist band, AS WELL as the backs. So really, if I don't trim the front trouser pattern first, I am going to have a smaller back waistline than the front.

Two patterns ago I had 22 cm waist on the front and 25 - 2 for the dart = 23 cm on the back. This pattern already has 23 cm on the front which means the backs will be 22 cm once the dart is allowed for.

I am not sure how to proceed. Do I take a cm off the waistband of the front at the side seam and taper to the knee... then draw the backs from that? Or do I make the backs wider at the waist regardless of the 90 cm waist band? It has all quickly become very unscientific.

Just sew it. You will see how the side seam run is.
When it is too crooked  you can make a simple seam shift(what you take from the front is added to the back)