20 November 2014

#SewingFrancoise: Bust Adjustments

Sewing the Francoise dress? Let's talk about boobs.

The pattern is fitted at the bust and - since our chests and boobies are all different shapes and sizes - you might find that you need to alter the bust on the pattern to fit your body. Today I'm going to show you three fitting alterations that you may or may not need - moving the darts, adjusting the pattern for a fuller bust, and adjusting the pattern for a smaller bust.

Moving the darts

Let’s talk nipples. (Teehee, nipples!) Our nipples don’t always necessarily land at the point where a sewing pattern hopes they will, in which case you may need to tilt the tip of the bust dart. You want the tip of the dart to point towards your nipples but end about 2cm / 3/4in before them to avoid them looking too pointy.

Personally I find the simplest way to tilt a dart to fit my body shape is to move it on the toile. Unstitch the original dart and refold it in the new position. Pin it in place and baste stitch (tack) it to check the position. Mark the new dart lines onto the paper pattern - like in the photo above, but your darts may be higher or lower or pointing in a different angle.

All you need to do now is “true” the dart, ie. get the dart leg lines the same length and redraw the side seam of the dart so that when you sew it together you don’t get any weird sticky-out bits at the seam allowance. Fold the dart closed temporarily, bringing the two legs (lines) together, folding the dart downwards, and taping it in place. Redraw a smooth side seam across your new (folded) dart, then roll a tracing wheel over it.

Untape and unfold the dart and you should see the perforations made by the tracing wheel – draw over these lines from the centre fold to make the side seams of your dart.

You may also want to redraw the waist darts so they are also pointing towards your boobs.

Adjusting bust fullness

If your boobies are on the larger side, you may find that the pattern fits your bust but is baggy above the bust at the upper chest and shoulders. Our sewing patterns include a 5cm / 2in difference between the full bust (measured around your nipples) and high bust measurement (measured around your upper chest just under your armpits). If you have around 7.5cm / 3in or more difference between your full bust and high bust, then what you can do is pick a smaller pattern size based on your high bust and then add extra room at the full bust by doing a full bust adjustment – AKA an “FBA”.

If, on the other hand, your bosoms are on the smaller side, you may find that while the full bust fits you, the upper chest and shoulders are too tight. In this case you can pick a larger pattern size based on your high bust and then subtract room at the full bust by doing a small bust adjustment, an “SBA”.

Measure your high bust (around your upper chest just under your armpits) and add 5cm / 2in. Choose the pattern size with that measurement at the bust to do your bust adjustment on. How much larger or smaller is your actual full bust measurement from the bust measurement on that pattern size? If it’s 2.5cm / 1in bigger, you’ll be adding 2.5cm / 1in when you do your full bust adjustment; or if it’s 2.5cm / 1in smaller, you’ll be subtracting 2.5cm / 1in when you do your small bust adjustment, and so on. Since the front dress pattern represents one half of the front dress (as the fabric is cut on the fold) – or one boob – you’ll be adding or subtracting half of that difference - 1.25cm / 1/2in in this example - to the pattern piece.

Both adjustments start off the same way by marking some cutting lines on your toile or pattern, slashing them open, then either spreading them apart or overlapping them depending on whether you want to make the bust larger or smaller. I’m going to show you how to do them on the pattern pieces since it’s easier to see what’s going on, but the same principle applies to altering the toile – you might prefer to make the alterations to the toile first, before transferring the changes back to the pattern, so you can be sure that you’re increasing or decreasing the fullness by the right amount for your body. Whichever method you choose, trace off copy of your pattern so you can keep the original one intact in case you need to go back to it.

Okay, let’s do this.

Mark the apex of your bust on your toile or pattern – ie. where your nipple lands. Now draw three lines fanning out from this point – one through the centre of the bust dart; one vertical line straight down the dress (parallel to the centre front line and perpendicular to the lengthen/shorten lines); and one diagonally through the raglan seam. We’re going to ignore the seam allowance so we don’t change the length of the raglan seam line – mark a point 15mm / 5/8in in from the cutting line on the line you just drew through the raglan seam.

Cut up the long vertical line to the bust apex, and from here up the diagonal line to the point 15mm / 5/8in from the raglan seam. Snip in from the raglan cutting line to a teeny bit before the point you just stopped cutting to, creating a hinge. (If you accidentally cut through the hinge or if it falls apart, don’t worry, just keep the pieces touching at this point when you come to move them later.) Cut along the dart line too, from the side seam to the bust apex, again stopping just short of it to create another hinge.

Full bust adjustment

Lay your pattern over a new sheet of paper, taping the centre front of the pattern to the paper to hold it in place. Spread the pieces apart at the vertical cutting line by the amount you need – either based on what you added to your toile or the amount you calculated based on your high bust measurement (see above). The bust dart will open up and the seam allowance at the raglan seam will close. Pin, tape or glue the pattern to the new piece of paper.

Now to redraw the enlarged bust dart lines. Draw a line through the centre of the new dart to the tip of where it’s been opened up. Mark a point about 2cm / 3/4in to the left – this is now the tip of your new dart. Draw in the dart legs from this point out to the points where the old dart legs started at the side seams. Redraw in the side seam lines, connecting at the centre line.

The changes we’ve made have also made the hemline uneven – now to tidy it up. Extend the centre front line downwards, and extend the hemline from the piece on the left across to meet the centre front line, making sure that there is a 90 degree angle at the corner.

And that’s your new pattern piece!

Small bust adjustment

Overlap the pieces by the amount you need – either based on what you subtracted from your toile or the amount you calculated based on your high bust measurement (see above). The bust dart will become narrower and the seam allowance at the raglan seam will open up. Pin, tape or glue the pattern in place.

Redraw the narrowed bust dart legs from the tip to points where the old dart legs started at the side seams. Draw a line through the centre of the dart, then redraw in the side seam lines, connecting at the centre line. (See the green lines.)

The changes we’ve made have also made the hemline uneven – now to tidy it up. Extend the hemline from the piece on the left across to meet the centre front line, making sure that there is a 90 degree angle at the corner. Cut off the piece below the line you just drew.

And that’s your new pattern piece!

I'll be back soon with some more fitting tips for you...


  1. Tilly, you are just adorable. I can't wait to make my dress this weekend!

  2. I have to do a dart move, I have never quite need a FBA but with vintage patterns I know that is what I SHOULD really do to get a good fit. Sway back is my big issue. jo x

  3. Thank you so much for this, this is the best explanation of an FBA that I have seen, I could not get my head around how it could help but I now understand it! Thank you x

  4. I've finished the muslin and seem to have a problem requiring some dart moving. I have never done it and honestly don't quite understand where exactly I should move those darts.
    Tilly, in the pictures you show how you move the point of the dart only, but not the dart legs. Is that what needs to be done if the darts are too high? (I prefer it this way rather than saying that my boobs are too low :-) We don't move the whole dart?
    If by chance you have a spare minute, will you please please please look at these two pictures of my muslin?
    I really don't have anyone else to ask.

    1. Ah yes, it does look like you need to move the darts down. You can either reposition the point of the dart, or shift the whole thing down. Unpick the dart on your toile, put it on inside out and repin it in a way that looks good to you on your body. Then reposition the dart on your paper pattern to match. Good luck!

  5. Thank you so much for this tutorial! I have one question - when making a FBA to the bust dart, what happens with the waist dart? I bought a dress pattern and I will have to do the FBA. I've tried it once on a simple bodice and it worked. But this dress makes it more complicated because of the second dart in the waist area. On your pictures I see exactly the same darts as they are on my pattern.
    So I mean, I will much appreciate your help!

    1. You might be able to leave the waist darts as they are, but it's difficult to judge without seeing the dress on you. Try doing the FBA as above, making a toile and seeing if you need to adjust the waist dart too. It might be simpler for you to repin the waist dart on the toile and transfer the changes back to the pattern. I hope this helps!

  6. I am struggling to make a simple sleeveless top. I'm putting the gaping armholes down to my big boobs! I've followed your tutorial and made a new pattern, increasing the bust measurement by 1.5in (3in in total). The problem is that now the waist is also 1.5in bigger and at the hem the pattern is 2.5in wider. I only really needed the increase at the bust-have I not followed the instructions correctly or do I need to try a different technique?

    1. Hi Ann, I think the best approach would be to pivot the cut bodice pieces away from each other at the waist instead of moving them away from each other. This way the dart and bust point will open up, but the hem will stay the same width.

      I hope this helps!

  7. Hi Tilly! I recently bought Love and First Stitch and love it! I am making the Morgan dress and doing an FBA on it. However, now the front bodice is longer than the back bodice and the side seams are longer than the back bodice side seams (a good inch and a half longer so can't ease). How do I fix that? Any suggestions would be great!

    1. Hi Kiki, The best thing to do would be to lengthen the hem of the back bodice so that the side seams match up. You can then decide after making it if you need to shorten it slightly. I hope this helps!

  8. Hi,

    I wonder if you can help me. I've followed this tutorial to do quite a large FBA on a simple shell top with sleeves. But It dramatically changes the shape of the armhole. Do you have any recommendations on how to sort this out? Should I somehow just re-draw the the seam? Many thanks

    1. Eek oh dear! Yes I would re-draw the side seam so that the armhole section is as similar width to the original pattern as possible. Perhaps make a toile to check you're happy with the fit before using fancy fabric!

  9. Ok, I've always angled the now uneven end back up to where it once was with a curved ruler. With this FBA, will I have to lengthen the back piece? Also, I've perused your site (mobile) and I need help with my swayback. It's extreme because I was a dancer for 30yrs. Once I do the swayback, the back darts will be wonky. I need help truing them up because they're double legged, rather than the typical dart. I do love the double legged dart for waist formation, as it defines your waist much better than the regular front bodice waist darts. Also, those French darts = love for the big busted, small waisted, big booty gal!


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