Pants Pattern Alterations

Last week in class I tried on the muslin made from the pants sloper, which was drafted up from my measurements. I think it's worth repeating my professor's words of warning: even a sloper drafted to your measurements isn't going to be perfect right off the bat, because the way those numbers are distributed is different on every person. Depending on whether you carry your weight in the front, side, or back, a 40-inch hip measurement could mean several very different things. One's legs could be 25 inches long, but the angle at which they come out of your hip, the amount of padding on one's inner thigh, and even the way one typically stands can all make a standard draft look terrible, even if it's based on actual body measurements. Still, that said, my muslin looked pretty good for a first try -- definitely better than all the vintage 60s pants patterns I've tried in the past!

We all had to take turns changing into our muslins and standing on the tabletops and our professor walked around telling our group members what to pin and cut into to get the fit right. What helped a lot for seeing where to make alterations was having the grainline, high hip, low hip, knee, and calf lines basted in. That way, we could see where things weren't hanging plumb or perfectly parallel to the floor all the way around.

I needed two vertical darts in the front crotch area to get rid of the excess fabric there. 

There's nothing quite so nerve-wracking as knowing that somebody is seam-ripping right by your butt. 

After everyone tried on and fit their muslins, we went over the kinds of pattern adjustments that might be necessary. One of our assignments is to make those adjustments on tiny paper pattern blocks for reference, so I thought you all might like to see mine. I apologize for the blinding yellow background; we were supposed to use a stiff backing and all I had were these binder divider tabs. I think it kind of helps you see where the cuts go, though, right?

#1) Crotch curve corrections: I did the back alteration to correct the mono-butt look. By giving more fabric to the back piece, one avoids having the fabric pulled so tightly across the butt that it becomes unnecessarily flattened. 

#2) If the grainlines angle in toward each other in a V, the above correction is necessary to accommodate the angle at which your legs exit your pelvis. 

#3) Full inner thighs: start with the same alteration as #2 but make several parallel cuts up the inner thigh portion, then pull the top part out so that the gap is almost parallel all the way up the leg. The cut flaps should overlap a little at the top.

#4) Front/back rise shortening: To change the crotch only, and not the side seam length, make a horizontal cut halfway down the crotch curve, leaving a tiny bit if the side seam uncut to use as a hinge. Pivot down to overlap the pieces, then redraw the curve. 

#5) Shortening the crotch depth all around: If there's excess fabric bagging all the way around, or the crotch hangs way below your body like gangsta pants, pin it halfway up the crotch and see how much needs to be removed. Make a horizontal cut all the way across the crotch and overlap (or separate if you need more depth), then redraw the crotch curve.

#6) Knock-knee alteration: If your legs come together at the knee and then curve back out, then you need a longer inseam only. By making a downward slash and using the side seam as a hinge, you keep the side seam the same length while extending the inseam. 

#7: Full abdomen, or as my prof puts it, extra chocolate storage: Cut across the middle of the crotch right under the dart and angle up to the waist at the side seam, then put a slice down the dart. Pull the top piece up and away, then redraw the curve. 

#8) Excess fabric at the crotch: If you can pin out a vertical fisheye dart at the front or back, cut from the side seam and up the inner side of the dart, then back out to the center crotch seam (leave a tiny bit attached to use as a hinge, though). Cut flaps like in #3, then push the pieces in until the hit the outer edge of the dart. The flaps will overlap a little bit in some place and spread out in others. I know this is a little hard to explain/see on the diagram, but this method of alteration seriously blew my mind, it was so amazing. I've always wondered how to translate the 3D changes to a flat pattern, and now I know!

#9) Lengthen back rise: If your pants are snugging up too much under the butt and giving you a wedgie, lengthen the back rise by making a few horizontal cuts across the crotch (keeping the side seam attached as a hinge), and spread them out. If the side seam dents inward too much, you may need to redraw the hip curve.

#10) Hyperextended calf alteration: My prof says she sees this most in people who have danced or done gymnastics, but the bulge of the calf hitches up the lower leg in the back. Cut a slash up the grainline, past the knee, and then make two symmetrical cuts angling up toward the side seam. Using the side seam as a hinge, rotate the two sides outward. It will look flared on paper, but on the body it will hang straight. 

#11) Waist alteration: Instead of just adding/subtracting at the side seams, which is what I had been doing previously, the proper way to add or take away inches at the waist circumference is to make a diagonal slash from the waist down to the side seam, then use that as the hinge point to spread or overlap the appropriate amount.

For all of these slash-and-spread moves, we literally cut and spread the muslins while the people were still wearing them, which let us adjust until there were no more wrinkles; this also let us measure exactly how much to spread the pattern pieces. It was an...intimate...experience for all involved, and thank goodness it was only ladies in the class. I wish I could show you what some of those slashed-and-spread bits looked like for real, but obviously I'm not going to post other people's butt pictures here! You'll have to look at my slashed-and-spread hyperextended calf alteration and imagine it on abdomens and such.

Look at how many inches they had to add in with an additional strip of muslin! The prof said she hadn't had to do one in a very long time, so I guess this is proof that I really do have burly calves?

You can see the diagonal fish-eye-esque darts under the butt, the hyper-extended calf cut, and the ripped open CB seam so as to avoid the mono-butt look. Yup, I had blue skivvies on that day.

I made three of my four adjustments (I couldn't figure out that diagonal dart, so I'll have to ask the prof about that one. ETA: answer is here) and redrew my sloper, so we'll see next week how it translates into a second muslin!

Oh, and for those who were wondering, the drafting book we're using is Building Patterns: The Architecture of Women's Clothing, by Suzy Furrer.