I lengthen the rise for better fit on trousers

Custom-fitting a pattern, in my view, is one of the most time consuming and worthwhile jobs in sewing.

What is the point of making clothes at all if they don’t fit like a glove?

I can easily buy a compromised fit ready-made, or, constrain myself to styles where the design is fully forgiving to my body shape being different from the block it was drafted to, so I refuse to accept a compromised fit when I spend upwards of 5 hours creating a garment.

Furthermore, my goal for sewing is to be skilled and confident enough to use - and wear - the highest quality fabrics, so not taking the time to perfect the fit makes this a meaningless expense.

Like everyone, there are places where I know my body routinely differs from the common block and standard proportions.

For a very long time, I believed that I had wider hips, and that my fit issues lay in needing more width in that location, but I came to realise that my fit differences were more pronounced in my fuller buttock and longer rise length, neither of which is fully addressed by adding width at the hips.

Lengthening the rise means adding vertical length between the waist and crotch line — usually by slashing the pattern horizontally and spreading it along a Lengthen or Shorten (LOS) line placed above the crotch curve.

It adds room for a longer torso or higher sitting waist. It helps if trousers feel too low in the rise or tight when sitting, that may feel fine when standing.

• “rise” = the more “vertical “ part of the crotch seam

• “crotch curve” = the curved portion of the crotch seam, that wraps under the body from front to back

• “crotch line” = the imaginary horizontal line that runs across the body at the base of the torso, where the legs begin. Often used as a reference point for rise measurements, it also happens to correspond with my hips at their widest point.

Nowadays, lengthening the rise is my go-to adjustment that often addresses fit issues across crotch length, buttocks and hips, and it is an easy one to do.

This is a vertical adjustment — it doesn’t change the shape, scoop or depth of the crotch curve, just its position. It’s like dropping the crotch point lower on the body, which can help with comfort. It doesn’t necessarily fix tightness across the seat - I may still need to make a full seat adjustment (e.g., scooping the back crotch curve or adding length and width to the back leg) - but I’ve learned I can place this bet on an easy first step, and it works nine times out of ten, saving me from a more involved adjustment.

Knowing this means I now typically re-draft the pattern before even attemping the first toile, or even without tissue fitting.

To make this work, I rely on taking a few key measurements from the pattern pieces - and I will redraft the pattern on the basis of these measurements alone. Then I make the first toile.

Most of the time, this works.

Lengthening the rise is a clean, efficient adjustment with very few downsides, especially when done within reasonable limits

Here’s how I do this.

How I fit and redraft trouser rise

When I encounter a new trouser pattern, I most commonly:

Select the closest size for my waist

For me, that is usually a Size 14 in a vintage pattern, perhaps a Size 12-14 in a new pattern.

Measure the full crotch length, seam line to seam line

Then I measure the crotch length, without seam allowances and compare it to my own - 28”. It almost always falls short, around 26 1/2”, maybe as short as 26” or 27” at the outside.

It is very common for me to lengthen the crotch seam usually around 1 1/4” to 1 1/2” total.

Divide the difference in two

I prefer to evenly split the difference between front and back.

Add a Lengthen-or-Shorten line

I draw an LOS line on both front and back, that is perfectly perpendicular to the grainline.

I try to avoid bissecting any darts or notches.

Trace the new pattern pieces

I overlay tracing paper and trace around the full leg up to the LOS line, including all notches and the grainline.

I also trace the LOS line, then draw another line above it at the distance I calculated earlier.

I shift the pattern underneath to match the LOS to the new line, ensuring the grainline stays aligned or parallel.

Then I trace the remaining upper part of the trouser leg, including darts, pleats, tucks, etc. A small amount of blending may be needed between original cut lines to smooth the side seam or inseam.

Adjust additional pieces

If the pattern includes a fly shield, fly facing, pocket bags, or pocket facings, I lengthen those too. I match any notches, draw an LOS line, and lengthen by the same amount as the rise adjustment.

Exceptions

The exception to this rule is if I am working to a very slim leg and fitted trouser, I prefer to redraft the back piece for a fuller seat, and a little at side for my wider hip.