Mono-butt!

Picture by Alex-501, used by Creative Commons license. A good example of mono-butt (as well as poor fit all around).

​Think hard... when was the last time you heard anyone say they were happy with their jeans?  I can't remember, myself.  If the topic of jeans comes up, everyone always has a litany of complaints.  Here are mine:

1. I hate low-rise.
2. I hate skinny thighs.
3. Not a fan of spandex.
4. What's up with mono-butt?   

​So if we all complain, why do we all live in jeans?  Because we've all had at least one perfect pair, and we remember how it felt.  We're in love with a fantasy of jeans, a platonic ideal of them. 

But the American obsession with denim is not my topic today; mono-butt is the subject du jour.  Mono-butt is when the seat of the jeans is ill-defined, like a bubble instead of buttocks.  This means that the crack is bridged by fabric (making a cave-like sauna inside), the legs have limited range of motion (you can't lift your leg without pulling the fabric from the other leg), and the fabric gets stressed on the center back seam.  And this look seems to be everywhere, on men's jeans and women's.  So unattractive.  "Buttocks" is plural for a reason, people!  I'm not asking for an extreme wedgie or anything, just a subtle bifurcation to make me feel like a woman instead of a baby in a diaper. 

AT LEAST I'M NOT ALONE...

Various sewing bloggers I follow have the same issues with the butt area on RTW jeans.  Kathleen Fasanella, who writes the Fashion Incubator site about sewn product manufacturing, posts various pictures of terrible fit and her ideas as to why this look is so common.  (The comments section gives the interesting tip to buy cowgirl jeans, which are cut higher in the back-crotch to allow greater range of motion for climbing onto horses.)  Amanda Wynn resolved to draft her own jeans, because she wants the flattering fit she says was common in the seventies but is rarely found today. 

SO WHAT'S TO DO?

When I made the charcoal jeans, I was working with a commercial jeans pattern, and I got this back view:

The fit was pretty close to the jeans he wore in that day, so I guess it's acceptable in the world, but this is not what I want.

But when I searched online for fitting solutions I found very little.  I wasn't even sure what search terms to use, so I spent the night querying Google with things like "how-to pattern alteration monobutt" and "bifurcated rear" and "fixing monobutt" and "getting better definition in the seat of jeans"... Google was confused.  Here's what I finally found:

• ​​The Colette Patterns Pants Fitting Cheatsheet, which didn't specifically address monobutt or jeans, but helped me rule out other problems. ​
• Pattern Making: Pant Rise; in the comments section people talked about the general crotch shape, a U or a V, and Maddie Flanigan pointed out that jeans have a narrower V shape because they are meant to fit differently and because denim stretches. 
• ​Finally, the ever-helpful Cation Designs shared her experiences in a muslin-fitting class, and included some marvelous diagrams of ways of altering pants patterns.  I think the very first one (Crotch curve corrections) was what I had been looking for all along... 

ONE BUTT AFTER ANOTHER...

After finishing the charcoal jeans, I still had two more pairs to make for my client.  I decided to apply the crotch curve correction to the pattern and make the next pair with it.  I started by adding 1/4 inch to the pattern:

First I taped paper behind the crotch curve and marked the original sewing line (dotted line inside seam allowance).

Then I drew the new stitch line (dotted) and its new seam allowance (solid)...

Finally, I trim the excess away. Let's see how this works...