How to alter sewing patterns for fuller busts

We all come in different shapes and sizes, so there will naturally be times when we set out on a new dressmaking project, and spread out the paper pattern lovingly in front of us, only to wonder how to alter sewing patterns for the perfect fit.

We’re so happy to welcome Claire Tyler to the Gathered website today, as she’s here to help with just that! She’s put together this guest post with her top tips for all those of us who need to adjust patterns for fuller bust sizes. Read on for her top tips for how to adjusting patterns to enlarge the bust.

Get to grips with your FBA! (Full bust adjustment)

“As a dressmaking tutor one of the most common fitting issues I come across is the bust. Students come to workshops with stories of how they have tried to make patterns fit but once they learn how to do a Full Bust Adjustment they don’t look back – some students come along to sewing schools with a handful of patterns and we spend the time adjusting them all so they can go away and make them up.

If you have a full bust you will have tried many ways to adjust a commercial pattern to fit – adding at the side seams, center front or just buying a larger pattern. This will rarely give you your desired finish, and you can end up with a garment that doesn’t fit at the armhole, neck or back – it may fit around the bust but everything else will be too big.

One important thing to know is that most of the larger pattern companies draft for a B Cup, this is a dressmaking B cup not a ready to wear size. In dressmaking a B cup means that your Full Bust measurement is 2in (5cm) bigger than your High Bust measurement (the high bust measurement is taken above the bust under the arms). Here’s a bit more about how it works…

Standard dressmaking cup sizes

Difference between high and full bust:

• A Cup: 1in
• B Cup: 2in
• C Cup – 3in
• D Cup – 4in

Don’t worry too much about cup sizes – it’s really more about getting the correct measurements. To choose the correct pattern, take your High Bust Measurement and add 2in, this will be the pattern you will buy – for the example below this would equal 38in. The difference between the High Bust and Full Bust below is 5in, take away the 2in that the pattern allows and the Full Bust Adjustment needed would be 3in.

For example:

• If the Full Bust (FB) measurement is: 41in
• And the Half bust (HB) measurement is: 36in
• Then the difference between FB & HB is: 5in
• Take a standard dressmaking pattern (B Cup): 2in
• And adjust by: 3in

There are several different bodice types, on the workshop I teach how to adjust a bodice without a dart (like a t shirt), a bodice with a side dart and a Princess line bodice. This covers most shapes so hopefully you will get a good idea of how to alter different designs.

Before each type of full bust adjustment we also need to look at the bust point – this is the fullest part or apex of the bust, we are all different and it is important that the bust point is correct for you – we don’t want darts pointing above or below our bust! The measurement is taken from the shoulder seam at the neck to the apex. You can do this with a tape measure or pin your pattern at the shoulder, place on the body and line up the CF. Mark your bust point on the pattern (if you are doing this be careful not to mark your clothing if using a marker pen)

Charlie Moorby

See author's posts