How to make a Full Bust Adjustment on a princess seam

Hello! Today you will learn how to adjust the bust on the Clementine knit dress and top. This tutorial can also be used for other princess-seamed garments too, but today we will be using Clementine as our example pattern. 

Now, Clementine is for knit fabrics. The beauty of stretch fabric is that we can often avoid bust adjustments. However, in this case, the correct shaping of the seams is going to make a big difference to highlighting the bust in a more flattering way. By providing more room for the bust, we also stop the fabric being stretched so tightly across the bust. Here is a sneak peek at the difference we have made to the fit - at the end, I will show you even more comparison pictures!

Now, I myself have no need of such an adjustment, but am lucky enough to have a lovely lady in my life that does. 

So, how do we decide on which size to make?

First we look at the measurement chart. Her bust falls into the size 36. Her waist falls into the size 38.

Now, what size you start with may differ based on what your frame is like. She has a smaller frame up top, so her shoulders fit into the size 34. So we’ll start with a size 34. Tip: A good way to check what size your shoulders fit into is to measure across the back of the pattern, take off the seam allowance, and then compare that to an existing knit garment that fits you well in the shoulders.


Note: This pattern has been graded out from a 34 to a 36 in the waist, but this does not affect the tutorial. Use the size at the waist that is correct for you.

Step 1

On the body, measure down from the shoulder to the bust point, keeping the tape vertical. For my client, this was 29cm.


On the pattern, measure the same spot: measure down from shoulder (keep the measuring tape parallel to the grainline). Mark the wearer’s bust point. For larger busts this will be lower than the pattern’s bust point. You can see on this image where the pattern’s bust point is (indicated by a notch). And you can see how much lower the bust point should be for my client. Mark this on the pattern on both pieces.

Step 2

On the Side front, draw a line from the side seam to the bust point notch. Draw the side seam and the princess seam on the pattern piece (on this pattern, seams are 6mm). You only need to do this in the area you are altering the pattern. Slash from the pattern's bust point to the side seam that you've marked in, and clip from the edge of the pattern piece to the side seam. This creates a hinge, which means that when we pivot the piece open, we are not affecting the length of the side seam.

Add a wedge through the Side front (see picture below). I opened it up by 2.5cm (1"). This is a good standard amount to add to go from a B-cup to a D-cup. First, mark in the seam line along the princess seam in that area.  Make sure you measure this added amount at the seam that you’ve marked, not at the cut edge of the pattern.


Now, we need to alter the Front to match the extra length we have added to the Side front. On the Front, mark a line perpendicular to the centre front, intersecting the bust point notch. Slash the pattern piece through this line.
Add length to the Front by sliding the piece down, making sure each piece stays straight along the centre front (see picture above). When you lengthen the Front, make sure the amount you add is equivalent to the amount you spread the Side front by. Again, measure at the seamlines, NOT the cut edges. This will ensure they sew together correctly. Tape in paper behind the pattern pieces.

Step 2

This has already increased the amount of curvature in your pattern. However, I also want to alter the princess seam so that the fullest point of the pattern matches the new, lower bust point I have marked on the pattern. And while I do that, I’m going to add some extra fullness to the bust too.

Add to the side bust at the new, lower bust point (I added ¾” (2cm)). This is a little bit less than I added to the length, because I don't want to make that curve too extreme. Blend to nothing above and below, smoothing it out so it meets the original lines gracefully. I free-handed this, making a natural curve, but it may need to be tweaked on each individual person! You’ll see how this makes extra space for the bust! However, by increasing the bulge in this area, this also increases the length of this seam, which we will address next. 

 

You can see here that I have also re-drawn the grainline, coming up from the hem so it is a straight line again, and have crossed out the old one. Also, blend the side seam outwards a little bit to fix the small divot that the pivoting has created (you can see this has been done in the above photo).

Side note: I have seen many badly-done full bust alteration tutorials, where they add to the waist or alter the side seam to a drastic angle. We don't want to add to the waistline, or we will be creating a baggy sack all the way down the front of the dress, which is totally the opposite of the point of this design! We also don't want to drastically alter the side seam, as that is not where the body needs extra shaping!

As you can see above, when I smoothed out my lines in the Front pattern piece, I also added a little bit to the Front. However, I didn’t want to flatten out the curve too much, which is why I added the extra volume mainly to the side bust. Adding a lot of room on the Front pattern piece will straighten out the curve, leading to an unflattering style line.

Step 3

Measure the length of the Side front and compare to the Front. I had a difference of 2cm, so I added that in to the front by again taping in more paper. (You can see how I could have added all the length into the Front last of all instead of in two stages, but here I show it in stages so you can visualise how the different steps of the process work.) Just remember to compare the seamlines of the garment, not the cut edges.


OK Guys! We did it. We’ve got a newly curvy pattern with more room for the girls. Let's congratulate ourselves with some nifty comparison pictures! I padded out my mannequin's bust to reflect the full busted figure we are altering for. The unmodified (B-cup) pattern is shown in burgundy. (This is a size 34 all over which is why it also looks tighter in the waist than the blue one, which is a size 36 in the waist). I mocked up our full bust variation in blue but left the neckline and sleeves unfinished, since all we need to compare is the princess seam. All the other pattern pieces are unaffected by this pattern alteration!

Hope this is helpful for you. Please do share your results and if you have any questions, ask away!

2 comments

  • Thanks Kaz! That is awesome to hear. :D

    Jo
  • Your directions seem very thorough and clear! This post and your elegantly simple princess-seam design make me want to try the pattern, even though a knit dress hasn’t even been on my radar.

    Kaz

Leave a comment

Please note, comments must be approved before they are published