In her comment to my latest post, Barbara asked if I could explain how I did the swayback adjustment on those trousers. And well, that's not such a difficult question to answer...
Before I start, however, I need to come up with a little disclaimer: I have often complained about how the 'swayback adjustment' is the most over-exposed pattern alteration in the sewing blogosphere. In most cases, this was about bloggers adjusting dresses or coats on which they might have done well to check the pattern's waist length. And yet, I've gone and used this term myself.
So, to avoid any confusion, I'll explain what I think my alteration on trousers is: a flat-butt-adjustment. I like high-waisted trousers, which made this adjustment needed. With a lower rise, the only 'issue' you would have, would be that the back waistband would sit a bit higher on your body than the front. Which, with a lower rise is not such a bad thing...
To show you what I did and why I did it, I will have to show you some close-ups of my behind...
This is it in my new trousers.
And this in my side-buttoned ones.
The light wasn't great and the focus is a bit off, so I'll add a side view to display the problem: There's a horizontal fold just below the waistband. Even when I'm not wearing heels.
I started to be aware of this fitting issue a while ago, so I was determined to fix is for my next pair of trousers. To alter it, I simply pinned the excess fabric on the side-buttoned trousers (for this, you would have to make a muslin if you're dealing with a new-to-you commercial pattern), took them off, measured what I had pinned and substracted that amount from the top of my trouser sloper.
In my case, the excess was at center back and tapered to nothing at the side seam. If you have a similar problem, you can use this type of flat-butt-adjustment. If the excess also exists at the side seam and/or at the front, you are dealing with a pattern in which the waist-to-hip distance (vertically) is larger than yours, and you should take out some of the overall height.
And finally, to answer a question nobody asked: both these pairs of trousers have straight waistbands. In my personal experience, straight waistbands work well on high-waisted trousers, when placed from the natural waist upwards. That's what you see here. I would never use a straight waistband on trousers with a lower rise. The vast majority of women, myself included, has curves in the waist-to-hip-area. And curves are not served well with a straight piece of fabric.