More trouser pattern thoughts

Continuing on with some of the topics that Handmade PHD is attempting to make sense of through exploration...

Side seam length and shape. 

Length- the front and back side seams in her sample trouser pattern should be the same length. In most trouser patterns they are. Is there a time when the lengths could be different? Yes, if it is an intentional design feature, or sometimes for shaping. (see calves below).

But,,,,In general, the side seams do not have to be the same shape at all. Especially from teh knee up to the waist.

Picture here shows a 1950's German draft, a 1920's draft and a 1970's draft for men's trousers.

 

Sometimes they are the same shape - as is the case of pyjamas or the flat block referenced in the previous post

If you do a bit of research you can see that traditionally men's trouser draft will not have the same outseam shaping on the front and back. The waist to hip ratio for men is generally less than for women but we must remember that shaping needs to reflect the body, and the body shape needs to be accommodated regardless of gender. If the hip is not full at the sides, there is no point to putting the shaping there. If it works for a particular body shape -great- but it is not the only way, nor necessarily the best way to go about it.

 

Side seam shape- if the outseams of a trouser are the same shape, or almost the same shape the trouser block could have been developed from a skirt pattern

  Patterns shown here from More Dress Pattern Designing by Natalie Bray.  

This shape of pattern development was very common in the days when trousers were more of a novelty garment for women. It puts more waist suppression in the side hip area, and the patterns tend to have a straighter CB seam angle (smaller amount of waist suppression). It is certainly much more common practice in women's patterns then in men's.

Inseam length.

The inseams from hem to knee in her sample trouser pattern should definitely be equal on the front and back panel. I'd argue for them to be equal completely but there are bigger issues with the drafting here.

The back inseam from knee to the tip of the fork/crotch is on more of an angle than the front, so naturally to keep the measurements equal, when drafting, it will drop down just below the horizontal crotch line at block development. Thinking it has to be on the same horizontal crotch line as the front is incorrect. You can see that in the Bray draft above.

As the angle of the back inseam increases, not only does the thigh size increase, but the bias of the fabric comes more into play. Bias will stretch out (more in certain fabrics) so sometimes the back inseam is shortened to account for bias stretch.

Lastly, in some trousers drafts, the back inseam is shortened to clean up the amount of fabric under the seat. Stretching the back inseam up with the iron before sewing it to the front, leaves the section under the body (before the seam turns vertically) lower.  Makes for a better fit in tailored trousers.

Calves                                  

An example of uneven seam lengths can be seen in some drafts which provide a bit of shaping for the  calves. You may see drafts/patterns where the back inseam and outseam from the knee to the hem are drawn with a slight convex curve. This increases the seam length relative to the corresponding seams on the trouser fronts. The extra length is eased in and provides a bit of shaping for the calves, and it increases the width over the calves as well.  This can be useful with very narrow trousers, or for people with prominent calves.

Knee shaping

You might also see some close fitting or speciality trousers drafted with a dart in the inseam and outseam at the knees to create a pocket at the knee. This is most often a style consideration.

next post - looking at the waistline .....