Before we get started, it’s important to note that not all gaping necklines are caused by the same issue. The solution will depend on which issue is causing your gaping neckline, and whether you’re adjusting your pattern pieces or a finished garment.
Firstly, it’s important to note that 99% of woven necklines need to be stabilized to prevent them stretching out during fitting and sewing. You can either staystitch or use an iron-on interfacing tape.
Issue # 1: Too broad across the shoulders
Sometimes neckline gaping is caused by wearing too large a size for your upper torso/shoulder area. To see if this is the case for you: smooth the neckline flat across your body, pushing the excess to the sides. If the shoulders now hang off your body, they’re definitely too broad for you. If you can’t smooth the fabric out to the sides, the gaping is the result of something else.
Image credit: @joy.margot, used with permission
Narrow Shoulder Adjustment: Method 1
If you’ve made a toile to check fit, you can do a narrow shoulder adjustment on your pattern pieces. When the shoulders of a garment are too broad, the excess fabric creeps into towards the centre front while the shoulder seams fight to sit correctly.
Some patterns come with an adjustment line for narrow or broad backs. If your pattern doesn’t, draw a vertical line down from the shoulder, starting 3 cm (11⁄4 in.) from the armhole and ending just below the bottom of the armhole. Draw a second line out to the side of the pattern, at a right angle from this point.
Cut along the two lines, and slide the armhole side over, overlapping the paper as much as the shoulder seam needs to move by.
Use a ruler and pencil to re-draw the side seam and shoulder seam. You’ll need to the same on the back piece to ensure the shoulders are the same width.
Narrow Shoulder Adjustment: Method 2
If you’ve already cut your fabric, completed your garment or are adjusting a ready-to-wear item, the quickest fix is to add a neckline feature like darts or gathers at the centre of the neckline. This will involve the least amount of unpicking and can add an interesting design feature to your neckline.
Issue # 2: Neckline is too wide
Often with a very wide neckline like a boat neck, the shape of the neckline sits much further out than we need. Hands up if you’ve ever been irritated by a neckline revealing your bra strap or falling off your shoulders! As a petite gal with a full bust, this is a common fitting issue for me. Luckily, it’s a simple fix.
Narrow Neckline: Method 1
This adjustment can only be made at the toile stage. Mark your front pattern piece as indicated by the red lines, and cut.
Slide the cut section away from the shoulder, until you’ve achieved the neckline width you want.
Draw a new line reconnecting the two corners of the shoulders, and extend the centre front line up towards the neck. You can now trim away the excess pattern at the centre front and shoulders, and fill in the space created by the adjustment.
This alteration must also be done to the back too, or the shoulders won’t match! You’ll also need to adjust facings and collars, if applicable.
Narrow Neckline: Method 2
If you’ve already cut your fabric, completed your garment or are adjusting a ready-to-wear garment, you can try raising the shoulder seam up, as this will reduce the neckline width. Work in smaller increments, as taking up the shoulder too much will also make the armholes smaller and shift darts and waistlines.
Issue # 3: Too much excess at neckline
If neither of the above solutions work for you, it’s likely that there’s just too much neckline for your chest area. Please note that you’ll need to make these fit adjustments on a toile before cutting into your final fabric. There are two methods for this.
Remove Neckline Excess: Method 1
This method is suitable for patterns with a side bust dart, and is the best method to use if you’re full-busted.
In this photo you can see the areas where I have pinned the gaping into a “wedge” or dart. Once you’ve pinned the excess, you can apply these changes to your pattern piece. Mark a wedge or dart on your pattern that matches the wedge you pinned on your toile. The dart legs should meet at the bust apex. Draw a line through the centre of the bust dart to meet apex.
Slash through the dotted line in the centre of bust dart leaving a tiny hinge at the apex, then slash the line of the neckline dart that’s closest to the armhole. Swing the cut section over to meet the solid line of the neckline dart.
The bust dart has been opened up to become bigger, and the neckline is now smaller. The neckline is now uneven and needs to be blended or smoothed out. You’ll need to redraw the dart legs and add paper to fill in the space on your pattern. Don’t forget to adjust your facing pieces too!
Remove Neckline Excess: Method 2
This method works best for patterns without side bust darts, and if you’re not especially full-busted.
Mark a wedge or dart onto the pattern that is as wide at the neckline as the amount pinned out. The legs should meet at the armhole in an area that won’t affect any notches.
Slash along the dotted line, leaving a hinge at the armhole. Swing the cut section over to meet the solid line of your drawn in wedge.
Whilst the neckline is now smaller, there’s a step or uneven line which needs to be redrawn. The armhole edge may also need to be smoothed out if a bump has appeared at the hinge point.
Hopefully one of these six methods has worked for you! You can finds heaps more sewing inspiration, tutorials, tips and tricks on my blog, YouTube channel or by following me on Instagram. I’m in the process of streamlining my Elevate Your Sewing membership and rebuilding the course platform. You can sign up to the waitlist here to be first in the queue when it re-launches!