For me, by far the most perplexing garment to fit are pants. They must fit up and down and around as all other garments but they must also have the correct crotch curve shape and length and fit around 3 "cylinders" (the torso and 2 legs). The fit adjustments are oftentimes counterintuitive.
Over the years, I have taken online classes and attended every pant fitting class offered in the sewing expos I have attended. Each class offered new insights as to why pants fit and don't fit. The most beneficial class I have taken was a 3 day workshop offered by the NJ Chapter of the ASDP (Association of Sewing and Design Professionals) taught by Karen Bengtson (member of the Colorado chapter). You can read more about the process in my previous post.
The pants pattern was based on the methods and techniques developed by Joyce Murphy who also wrote an article in the December/January 2006 Issue 122 of Threads magazine entitled, "Adjusting Pants from Waist to Seat." It was a fascinating article where she explained the concept of body spaces and how they relate to the crotch length and more importantly, how there are an infinite number of shapes of body spaces. She also explained why the commonly recommended adjustments often don't work.
I am very happy with the result but I want to understand why they fit. Below is my analysis.
Here are the Joyce Murphy pants, front view:
And most importantly for me, the back view. There is a little bit of a wrinkling below my derriere on the left side due to my left hip being lower but it doesn't bother me:
|Big 4 pant pattern muslin - Front|
|Big 4 pant pattern muslin - Back|
In the photo below, I placed the Big 4 pant pattern back (the tissue) on top of the Joyce Murphy pant pattern (white paper) and you can see how the Joyce Murphy pant pattern has a longer back crotch length!
Another very important factor is the crotch curve. At the risk of over sharing, here is mine. I obtained it using a flexible ruler. I placed a red rubber band where my inseam is located. Given that I have a flat derriere, I was absolutely astonished that my shape was so round, almost a perfect circle - ha! I did this repeatedly to make sure I got the shape right, because I just couldn't believe it, but I kept coming up with this. The space inside the flexible ruler is what Joyce Murphy calls "body space." Everyone has their own unique body space:
So when I took the above photo and drew in "legs", the flat derriere (as well as tummy - boohoo) becomes evident. Funny how the eye can distort reality (or is it wishful thinking)!
Another factor at play here is the angle of the center back seam. The more angled the seam, the more it can accommodate a curvier derriere and the opposite is true for a flat derriere. You don't need much of an angle for a flat derriere. Why?
Same goes for pants! The curvier the derriere, the larger the "dart" needs to be so a greater angle would help. Someone with a flat derriere, like myself, needs a smaller "dart" or an angle that is at less of an angle. I first heard of this center back "dart" in a Lorraine Henry class at an expo.
So for me, in order to get pants that fit nicely, I needed to add to the back crotch length, reduce the front crotch length, make sure the crotch curve mirrored mine and reduce the angle of the center back seam. Whew!
There is a wealth of information out there on fitting pants and many different methods. Finding the method that works for you requires much experimentation but most of all perseverance and patience.
Now I want to use this pant block to create pants with different leg shapes and in different fabrics. I am sure these changes will present their own challenges, especially different types of fabric. Hmmmm...