9 July 2018

Fitting the Seren Dress

Seren dress sewing pattern - Tilly and the Buttons

Itching to get your Seren sundress off your cutting table and into your nearest field of flowers? Before you get sewing, let's talk fitting.

As the bodice on this dress is fitted, it's worth taking the time to make a toile (AKA "muslin") - a mock up in cheap fabric with similar qualities to your final fabric - so you can make any alterations needed to get it to match your unique body shape. I wouldn't worry about toiling the skirt part.

Alternatively what you could do is make your first version of the whole thing as a "wearable toile", a version in nice-enough-but-not-expensive fabric so you can wear it if it does fit you first time, or if it needs altering it's not the end of the world.

Seren dress sewing pattern - Tilly and the Buttons

In this post I'm going to go through the most common fitting alterations that you might want to make to your pattern - if you already know you usually need to make any of these alterations, go ahead and adjust the pattern before you make your toile. Or if you're not sure, make your toile first and adjust the pattern based on what you need to add or take out of your toile.

We're going to cover:

  • Choosing your size
  • Lengthening the bodice or skirt
  • Shortening the bodice or skirt
  • Combining pattern sizes
  • Bust adjustments
  • Adjusting the dart position
  • Altering the strap length
  • What to do if the neckline gapes
  • What to do if the front opening gapes at the bust


Please bear in mind that, depending on your shape, you may not need to make any changes, or only one or two, so please don't feel intimidated by this list! It's worth putting a bit of effort into fitting to get clothes that are tailored to your unique set of curves - after all, that's one of the benefits of making them yourself - but equally it's important not to over-fit. Remember, this isn't a couture gown, it's more summer picnic or wedding disco attire, so it's going to move with you :)


Choosing your size

Using a flexible tape measure, find the circumference of your:
- bust - take the measurement at its fullest point ie. around your nipples
- waist - where you bend at the side
- hips - fullest part

Check the tape measure is sitting level with the floor - it can help to turn to the side and look in a mirror to check.


Circle your measurements on the ‘Body Measurements’ chart in the pattern instructions. If your measurement falls between a size (for example, if your bust is 35in rather than 34in or 36in), it’s usually better to choose the larger size as it’s easier to take the bodice in as you're sewing if it’s too big than to let it out if it’s too small.

If your bust, waist and hip measurements fall into the same size, refer to the key on the pattern sheets that shows the solid or dashed line for your size – that’s the one to follow when you cut out your pattern. Don't worry if they fall into different sizes - that's totally normal! See 'Combining pattern sizes' below...

Altering the length

The 'Body Measurements' chart includes nape to waist measurements, which is the length from the nape of your neck (the nobbly bit at the back) to your natural waist. If your torso is 1.5cm (5/8in) or more longer or shorter than this, it would be a good idea to adjust the bodice length for your size using the "lengthen or shorten here" lines printed on the pattern.

You can also alter the length of the skirt if you want. The skirt already has knee-length and midi-length options, and if you want to lengthen or shorten them without changing the flared shape of the skirt, you can again use the "lengthen or shorten here" lines.

Here's how...

Shortening the bodice or skirt

Fitting the Seren dress - Tilly and the Buttons

Draw a parallel line above one of the "lengthen or shorten here" lines on the front and back bodice or skirt piece - the distance between the two lines should be how much you want to shorten it by. In the picture above I'm shortening the bodice by 15mm (5/8in).

Fitting the Seren dress - Tilly and the Buttons

Cut along one of the "lengthen or shorten here" lines and move the lower pattern piece straight up until it meets the line you drew in the previous step. Tape or stick it down. Re-draw the side seams into straight lines. If you're shortening the bodice, do this on both front and back bodice pieces, and shorten the front facing by the same amount.

Lengthening the bodice or skirt

Fitting the Seren dress - Tilly and the ButtonsDraw two parallel lines on a scrap of paper, joined at one end by a vertical line - the distance between the parallel lines should be the amount you want to lengthen the bodice or skirt by.

Repeat this once more if you are lengthening the bodice so you have a set of lines for both front and back pieces.

Fitting the Seren dress - Tilly and the ButtonsCut along one of the "lengthen or shorten here" lines marked on the front or back bodice or skirt piece. Place a paper strip with the set of lines on underneath the pattern pieces, aligning the cut edges with the horizontal lines, and align the vertical line with the long straight edge. Stick them down with tape or a glue stick. Extend the side seam line so it joins up and cut away the excess paper. If you're lengthening the bodice, do this on both front and back bodice pieces, and lengthen the front facing by the same amount.

Combining pattern sizes

If your bust, waist and hip measurements span different sizes, make the following alteration so the pattern pieces match at the waistband.

Fitting the Seren dress - Tilly and the Buttons

If you're combining different bust and waist measurements, on the back bodice piece, draw a straight line at the side seam joining up your bust size at the top and and your waist size at the bottom. The above photo shows a back bodice for a size 3 bust and a size 5 waist in green, and a size 5 bust and size 3 waist in orange.

Fitting the Seren dress - Tilly and the Buttons
For the front bodice, we need to temporarily fold out the bust dart so we can draw a straight line at the side seam. Fold the bottom leg of the bust dart in your bust size up to the top leg and tape it down so that the side seam is a continuous line, and the dart is folded down towards the waist. Redraw the side seam so that the sizes are merged, like you did for the back bodice.

Fitting the Seren dress - Tilly and the Buttons

Before you unfold the front bodice, roll a tracing wheel over where the dart is folded at the side seam. This will mark out the side of the new dart - go over these lines in pen. If you don't have a tracing wheel, you could make some pin pricks along this line.

Place the front and back neckline facings over the top of the bodice necklines, matching up the notches. Trace off the new side seam.

Fitting the Seren dress - Tilly and the Buttons

If your hips fall into a larger size than your waist, on the skirt, draw a tapered line at the side seam from your waist size at the top to your hip size at the first notch down. The above photo shows a skirt piece for a size 1 waist and a size 3 hip in green.

If your waist size is larger than your hip size on the measurements chart, I would just cut out the skirt in your waist size, otherwise the redrawn side seam (tested on the above photo in orange) will look a bit of a weird shape.

Bust adjustments

If your boobs are on the larger side, you may find that the pattern fits your bust but is baggy at the neckline. On the other hand, if your bust is on the smaller side, you may find that while the full bust fits you, the neckline is too tight. One way to resolve this is to choose a pattern size based on your "high bust", and then add or subtract room at the full bust. This is known as a full bust adjustment (FBA) or small bust adjustment (SBA).

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). Measure your full bust and high bust and work out the difference between them. If the difference between them is significantly more than 5cm (2in), you may want to try making a bust adjustment to the pattern.

To work out how much you need to add or subtract to the bust area, add 5cm (2in) to your high bust measurement. Choose the pattern size with that measurement at the bust to do your adjustment on. Compare your full bust measurement to the bust size of that pattern size (or your high bust + 5cm/2in) - if your full bust is 2.5cm (1in) bigger, you’ll do an FBA and add 2.5cm (1in); if it’s 2.5cm (1in) smaller, you’ll do an SBA and subtract 2.5cm (1in), and so on.

Since the piece is cut twice, the pattern represents one half of the change you need to make - so you'll be adding or subtracting half of the difference - 1.25cm (1/2in) in this example. Trace off a copy of the pattern pieces so you can keep the original intact. Make sure you trace off the notches and grainline arrow too.

Both full and small bust adjustments start off the same way by marking some cutting lines on your pattern, slashing them open, then either spreading them apart or overlapping them, to add or remove space at the bust.

Fitting the Seren dress - Tilly and the Buttons
To start, we need to set up the lines we’ll use to cut up the bodice. The first is a line the runs from the centre of the dart at the side seam, through to 2.5cm (1in) beyond the dart tip. This is the bust point. The second line goes straight from the bust point down to the waist seam, parallel to the grain line. I've marked the two lines above in orange.

Fitting the Seren dress - Tilly and the Buttons
The third line runs from the dart tip to the strap notch closest to the side seam. Mark a point along this line that is 15mm (5/8in) away from the cutting line.

Fitting the Seren dress - Tilly and the Buttons
Cut from the waist seam up to the dart tip and then to the point 15mm (5/8in) away from the neckline. Snip in the other direction at the point, so the pieces remain attached by a small ‘hinge’ at the sewing line. What we've done here is ignore the seam allowance to ensure the neckline stitching line stays the same length. Finally, cut up the centre of the dart, again leaving it attached by a little hinge at the dart tip.

Full Bust Adjustment

Fitting the Seren dress - Tilly and the Buttons
If you’re doing a full bust adjustment, pivot the two left-hand pieces away from the right-hand piece so that they open up at the bust point by the amount that you worked out above - 1.25cm (1/2in) in our example. Stick or tape the pieces down on a new piece of paper.

Mark a point 2.5cm (1in) back (towards the side seams) from the bust point and re-draw the dart lines from here to their original starting points at the side seams. The dart tip is a bit back from the actual bust point so you don't get that pointy boob thing going on!

Fitting the Seren dress - Tilly and the Buttons
The side of the bodice will have moved down a bit to accommodate a larger bust, so we need to even out the waist seam. Add a strip of paper under the pieces on the left and cut them so they join up with the waist seam of the piece on the right.

Small Bust Adjustment

Fitting the Seren dress - Tilly and the Buttons
If you’re doing a small bust adjustment, overlap the two right-hand pieces over the left-hand piece at the bust point by the amount that you worked out above - 1.25cm (1/2in) in our example. Stick or tape them down.

Fitting the Seren dress - Tilly and the Buttons
One of your dart legs may be covered by the extra paper - in which case it helps to cut it away so you can see your new, smaller dart.

Fitting the Seren dress - Tilly and the Buttons
The side pieces will now be shorter than the left piece as less room is needed for a smaller bust. Trim off the excess on the left piece so the waist seam is the same level. Trim off the same amount on the front bodice pattern piece too so they match up when sewn together.

Moving the dart position

The darts should end about 2.5cm (1in) from the fullest part of your bust so they don't end up too pointy. If the dart tips are coming up too high or low, they can easily be moved to a better position for you.

Fitting the Seren dress - Tilly and the Buttons
Mark on your toile where your nipples are, then mark 2.5cm (1in) away towards the side seam. Make a note of how much they need to be moved - for example, 2cm away from centre and 1cm down.

On your pattern piece, draw a vertical and horizontal line through the dart tip in your size and mark where you want your new dart tip to sit, following your notes from the previous step. Redraw the dart legs to meet at this point.

Altering the strap length

If the neckline is coming up too high or low, it can be adjusted by changing the strap length. This may move the dart tips away from the fullest part of your bust, in which case you’ll need to adjust them slightly (see above).

To shorten the straps

Fitting the Seren dress - Tilly and the Buttons
Draw two vertical lines along the long length of the strap, the distance between them being the amount you want to raise the neckline and darts by. Cut along one and move it along so it aligns with the other line you drew. Tape or stick down.

To lengthen the strap

Fitting the Seren dress - Tilly and the Buttons
On a scrap of paper draw two vertical lines, the distance between them is the amount you want to lower the neckline and darts by. Join the vertical lines to create a rectangle. Cut the strap in two along the shorter edge and insert the rectangle so the horizontal and vertical lines align. Tape or stick down.

What to do if the neckline gapes

Fitting the Seren dress - Tilly and the Buttons
If you find that the neckline of the bodice gapes slightly, pin out the excess fabric at the top of the side seam. Measure how much you have pinned away and transfer this to the side seam of the front and back bodice pattern pieces.

Re-draw the side seam above the top of the dart so that it is curved slightly.

Lay the facings on top of the bodice pieces and trace off the new side seams.

What to do if the front opening gapes at the bust

Fitting the Seren dress - Tilly and the Buttons


If you find that the front opening gapes at the bust, one option is to move the position of the buttons, ensuring one sits parallel to the fullest part of your bust.

However, this can throw off the spacing of the buttons. An alternative easy fix is to sew small hidden snaps (poppers) to the inside of the button stand. They are come in a variety of sizes and can be strategically placed to keep your button stands lining up beautifully! On the layer with the buttonholes, be careful to only sew them through the facing, not through the bodice itself, so the stitches aren't visible from the outside of the dress.

Seren dress sewing pattern - Tilly and the Buttons

That’s it for Seren adjustments. Fitting is a huge subject and we can't cover everything in one blog post - if you need more help or feel like geeking out, Fit for Real People by Pati Palmer and Marta Alto and The Complete Photo Guide to Perfect Fitting by Sarah Veblen will go into a lot more changes in detail (these are affiliate links).

Please don’t get bogged down or overwhelmed with fitting adjustments though – make one or two alterations if you think they are relevant to you, and don't stress. Chances are you're the only one who will notice any parts that don't fit perfectly - everyone else will be wowed by the stunning dress that you made yourself!