I recently started making a vest for my mom – who is a HUGE fan of vests… and we picked out a pattern, but the pattern had a large waist dart that we wanted to convert to a princess seam. This is because we wanted to be able to use a different fabric on the outside edges of the front! I had some beautiful Pendleton wool, but didn’t have enough for the whole vest, so we wanted to use it as an accent with a princess seam.

So in this tutorial, I show you how I changed the waist dart in the bodice into a princess seam! In the video, I even take you along through a couple test runs of the pattern and show you how I update my pattern after the first fitting.

Alright, so the video version of the tutorial is below, but if you want the written version just scroll on past the video!

But first, here’s what you’ll need!

What you need

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Video Tutorial

Written Tutorial

Alright for those of you who prefer to read the tutorial – on to the written version!

So first I traced off the vest front pattern piece that I want to alter. I didn’t want to cut up the original pattern piece in case I messed up, so tracing it off gave me another copy to work with and make my changes. I also want to mention – this piece may look a bit odd in shape – that’s because the collar is built into the piece, which is what that piece that sticks up above the shoulder seam is. But we don’t need to worry about that for this process.

vest front pattern with a large waist dart on a green cutting mat

Next, we need to draw in our new princess seam. So I used my french curve ruler to draw in a nice curve connecting the side of the dart closest to the side seam with the armhole. It’s up to you how you want your curve to look – I would suggest looking at photos to decide how angled you want your curve to be.

Then cut the pattern piece apart along the curve you just drew. This will be your new seam line!

Next, we need to add in our seam allowance to the part we just cut. You only need to add seam allowance to the top curved part, then blend it into the seam allowance where the dart used to be. I accidentally added seam allowance to the entire area, and it worked out OK, but it would be best to only add it to the top part where we drew in the new seam. You’ll need to add seam allowance to both the front and the side front pieces.

And that’s all there is to it! I would definitely recommend testing your new pattern with muslin or another inexpensive fabric before cutting into any nice fabrics. That way you can make sure the fit is good and make any adjustments to your pattern!

Also – below is a photo of the vest I made for my mom with this pattern (before I put the buttons on) – this picture was the one I sent her to get her input on button choice! ๐Ÿ™‚

I hope you enjoyed this tutorial and feel like you can take on turning your darted bodice pattern into a princess seam bodice! If you want more sewing and DIY tutorials I would love to have you sign up for my email newsletter! You can sign up below. ๐Ÿ™‚