Alert: This post is about modifying patterns for panties, aka women’s underwear. There are no pictures of me wearing said undies, just paper patterns. However, if straight talk about how panties fit and terms like “crotch length” make you uncomfortable, bounce now. 

When you use a PDF pattern, you download it, print it out, and then tape it together at the indicated lines.

Note: Unless you’ve hung a projector from the ceiling to project the pattern onto the fabric (aka: paperless). I haven’t done that yet, though I have downloaded a 3D-printer file for a widget that mounts a projector to the ceiling. And I did have a conversation with my husband about how he feels about holes in the ceiling. So… 

Then you cut it out. 

I’ll save you some squinting, I cut on the size-18 line. This pattern goes up to size 20. If you’re more abundant than that, there is a sister pattern “Acacia Curve” that goes larger.

This pattern has a front, a gusset, and a back. The reason there’s a separate gusset is so you can make a “completely enclosed” gusset, where the seams on both ends of the gusset are covered (it happens during construction with some rolling and folding magic). This is in contrast to the “pocket gusset” which is attached to a front-middle combined piece, and has only one seam covered. If this explanation is fuzzy, wait for the next blog post in this series, which covers construction. It’ll be clearer there.

The first thing I did was make a pair of panties using the default Acacia pattern for my size in a test fabric with the same characteristics as my intended “fashion” fabric. They fit in the hips, but had the same too-long crotch problem as commercial underwear.

Seriously!?! I’m short waisted; does this mean I’m short-crotched as well? Are they even related? Wait—are they?!?

Emotional revelations aside, it was validating to discover that the fit issues I’d been having with underwear are because of assumptions about what’s “normal” and not just that I’m buying the wrong style or size.

So, with the undies on, I pinched off the amount of fabric I needed to take out of the center to bring the back down. It looked like about two inches, which would be a lot. So I decided to decrease the middle by about an inch instead.

I remade the undies and tested them, and then decided to take another 3/4 inch off the front. 

Note: Yes, it hurts me not to use metric. I live in the U.S., however, where all the tools (and cutting mats) are imperial and have (mostly) given up the fight.

While I was taking off that extra 3/4 inch, I also took the seam allowance off the top and legs. It was in the way because I finished these hems with fold-over elastic, and I’d gotten tired of cutting it off.

I also decided that I’d rather have simpler construction and one less seam in a delicate area, so combined the front and gusset into a single piece. 

This third pair of test undies still rode up in the back by about an inch. However, there didn’t seem to be any more fabric to take out of the front or gusset, so I took an inch out of the back.

And re-graded to smooth out the curve with a hip-curve tool.

Note: Funny fact, when I left the PhD physics program to briefly pursue an MFA in costume construction (long story) I took a pattern-drafting class, which I loved because it was precise and mathematical. So I have all the pattern-making tools, and some facility with drafting, and yet am a complete novice at, and totally intimidated by, actually sewing. This has confused people in the past.

Here is the re-graded back piece.

One thing to note here, the version number written on the pattern. I was doing rapid iteration with multiple changes. Versioning each new pattern variation saved me from confusion and chaos. Highly recommend.

One more set of test undies, and… they fit! Perfectly. So extremely comfy and much more flattering than commercial panties. It’s like… (wait for it) … they were made for me. 😀

I was curious as to how much difference there was between the original pattern and what I’d ended up with, so I re-cut a new version of default Acacia, size 18, and laid it side-by-side with my final version.

Huh. They don’t look that different.

So I turned the pieces around to measure the overall change in crotch length.

Ah, there it is. What I’ve been complaining about. I had to reduce the overall crotch length by a whopping THREE INCHES to get them to fit me. That was three inches of wedgie built into every commercial pair of underwear.

Note: Sharp-eyed folks will see what looks like an extra 1/2 inch of difference. Remember that I removed 1/4 inch seam allowance from the waist of both the front and back pieces.

It is hard to explain how exultant I felt when I tried on the pair that finally fit. It is entirely possible that I high-fived myself in my studio. I may have done a dance of triumph in my undies. There were no cameras; the world will never know.

I traced the final pattern onto tag board. It’s a stiffer paper like that used in manilla folders, but has one side beige and one side green so you can immediately see if the pattern is right side up.

I then punched a hole in the pattern so I could put it on a hook and hang it from a rod (you can’t, and wouldn’t want to, fold tag board).

Here’s a tip that I didn’t think of until too late. I should have punched the hole in the exact center-front of the panties. That would have made it easy to place the pattern over fabric and center a motif.

And while we’re talking tips. If you are going to be doing lots of iterations on small pattern pieces, an 18 x 24” sketchpad is a wonderful thing. The paper was durable and just the right size for laying out undies. Much easier than wrangling a roll of paper, or fighting with unfolded grocery bags.

Having cleared the hurdle of creating a pattern that fits, I am ready to start creating panties in the fun fabric I’ve been saving for this moment.

I’ll talk about fabric choices and construction in the next blog post.