Adjusting Simplicity 4055


Okay, so you’ve seen so far that I’ve made three dresses based on Simplicity 4055, which is the commercial version of Jennie Chancey’s Regency gown pattern from** As you can tell, I’ve made a lot of adjustments to the pattern, mostly the bodice, to get it to work for me. I thought I’d detail them here so you can see how it was done. I’m not talking about basic stuff like lowering the neckline (by about an inch, otherwise it’s too high for most looks) or lengthening the bust to allow for any size over an A-cup (there are instructions available for that on Ms. Chancey’s website)— I’m talking about some structural changes for more period-accurate details.

Forgive my clumsy graphics– I’m not great at tracing things out using a laptop trackpad!

Shoulder seams

One of the biggest differences between the commercial pattern and an authentic pattern is the shoulder seams– the commercial pattern has them at the top of the shoulder, where we expect them to be from our modern patterns. However, Regency gowns shifted the shoulder seam much further back, and angled it to get a “diamond back” look.


This is simple to do– first, take your original pattern pieces (front bodice and center back bodice) and draw in the actual seamlines (5/8″ in from the edge, at least for this pattern). Overlap the pieces so the seamlines line up, and tape them together that way. Then trace out the whole thing on a new sheet of paper (the “baseline pattern”). You may also want to consider shifting the whole shoulder strap about 1/2″ closer to the neck– the original neckline is awfully wide and may fall right off your shoulder if you’re not careful. Similarly, the original armscye is just far enough off the shoulder that it constricts movement of the arm. 1/2″ of difference made it work for me, though your mileage may vary.


Place your front bodice piece onto the baseline pattern and draw in a new seamline further back on the shoulder, angling it with the long end towards the armscye. You’ll want the new seamline to be at least 1.5″ further back at the shortest point, with a nice sharp angle so it looks intentional.

Once you’ve drawn your new seam, add on seam allowances on either side.


Get a new sheet of paper and lay it over your baseline pattern. Trace out the center back piece (because it’s smaller and will fit on one sheet of paper), including the new seam allowance at the shoulder. Cut it out for a finished piece.

Then cut your new front bodice piece from your baseline pattern, cutting along the other seam allowance. Voila, all set!


Back side seam

Okay, I’ve referenced this before, but the original curved back side seam on this pattern is evil. E-V-I-L. I must have basted and ripped it out at least 3 times on each side to get it to fit properly, and even then I had extra fabric at the end. I know this is normal and I can just cut it off, but I couldn’t help feeling like it wasn’t working right, so I fixed it.

The first thing you’ll do is make another baseline pattern, this time for the back. Line up the back center (the one you just altered) and back side pieces together, so they form a whole back bodice. This will be difficult since (surprise!) the seam lines aren’t the same length. Do your best, lining up the waistline and the armscye as best you can. Trace around the whole thing.


To begin the alteration, I took out my back center piece and decided where I wanted my seamline to start at the armscye to get a real “diamond back” look. Remember, you’ll have a 5/8″ seam allowance at the sleeve too, so you’ll need to start the seam pretty close to the shoulder seam to get the right effect. Mark your starting point and draw a shallow curve towards the center back waistline. I ended up moving the bottom point about 1.5″ in towards the center. Remember, you’ll still be gathering/pleating most of the skirt back between the two seams, so leave enough room to do that. Your seam should be a very gentle curve.


So that’s your new seamline. Cut along the new line and lay the cut piece onto your baseline bodice. Just as you did with the front, trace that seamline onto the bodice and add seam allowances on both sides. Then take a fresh piece of paper and trace out the new side back piece, including the seam allowance. Adjust the waistline to straighten it out, and fix the underarm seam so it’s at a right angle to properly shape the bodice. Once you’ve done that, cut out the whole thing along the other seam allowance to make your new center back piece.


Now you’ve got new back pieces that will be much easier to sew together. Bonus, since the new seamlines are exactly the same length, you’ll be able to match stripes and patterns much more easily!

Skirt back

I’ve also ranted about this— how you get a bubble-butt effect if you cut the back skirt to have a “hump” in the back as drafted– and it’s a really simple fix. Just cut it straight across. As you can see, your bodice back waistline is perfectly straight (especially now that you’ve worked out the kinks in the back seams)– there’s no reason to make the back of the skirt anything but straight as well.

I would also recommend adding some extra width to the skirt– either by simply cutting it wider than drafted, or by adding a triangular gore to the center back. It’ll really help your dress look like a dress instead of a costume, especially if you have a light, flowy fabric. You could easily make your back panel twice as wide as drafted and it would look great. Use the triangular gore if you’re worried about pleating all of your fabric down to a narrow space on your waistband– it’ll reduce bulk and still provide a nice sweep at the hem.


One major pattern issue I have not addressed is the sleeve placement. Regency sleeves were set deep into the back to further visually narrow the back bodice– you can see in the photo above of the sheer white dress that the sleeve caps extend over the shoulder blades. I have no idea how I’d modify the sleeve pattern to do this properly, so I’m not going to try. Sorry.

Also, for my first dress I cut the back skirt panel in two, and instead of inserting a placket in a slash at the center back skirt as instructed, I just used the center seam allowance as my placket. It was SO much easier than cutting a slash and stitching in a separate placket (which I did on my sari dress simply because the fabric was so thin I worried about puckers in a long center back seam). I would recommend going this route if your fabric will support it.

Always, ALWAYS make a mockup of the dress bodice after you’ve made your pattern changes– for that matter, you should make a mockup even if you don’t change the pattern, because what works for one person may not work for another. If you’re afraid of wasting fabric on a mockup, buy sheets from Goodwill– at $1.99 per sheet (at least at my local store) I can get a king-sized sheet’s worth of fabric to play with at a price that’s far lower than anything I’ve ever seen in stores.

** It has recently come to my attention that the creator of this pattern is also the author of a “Ladies Against Feminism” website, which espouses many ideas that I simply cannot support. Without going into detail, I will simply say that I will no longer be purchasing any patterns from, nor can I in good conscience recommend that others purchase the Simplicity 4055 pattern unless it is purchased secondhand.





Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s