Savannah Swimsuit Full Bust Adjustment

We are working with a set of cups, because they are mirrored, you’ll want to divide the measurements you are adding into the pattern in half. As an example, we recommend adding the following measurement per cup size:

• D = add ½ inch
• E = add 1 inch
• F = add 1 ½ inches 
• G = add 2 inches
• H = add 2 ½ inches
• Etc… going up by ½ inch per mirrored cup size

NOTE – We’ve shown how to adjust a G cup using a 2 inch increase, as the example in these steps. Please use your own required measurement here as this is where the fullness is added. Our bodies are all different, which means you may find that you’ll need to adjust the pattern in different places, such as adding a little more to the bottom of the cups.

Cut the Outer Bust Panel, Inner Bust Panel and Top Bust Panel from inexpensive swim fabric – with the same stretch/composition as your final bikini fabric. Stitch these together using a ⅜ inch seam allowance.

Try it on. Mark the bust (nipple) point (red dot) onto the muslin piece. Place this muslin over the original Outer Bust Panel and Inner Bust Panel pattern pieces and transfer the bust point marking onto the pattern pieces.

NOTE – We recommend using a muslin piece to find the bust point as the pattern is designed with negative ease. This means the pattern piece won’t stretch across your bust and will make it difficult to find the bust point.

Take the Outer Bust and Inner Bust pattern pieces and place them onto tracing paper, lining up the bottom Under Bust seam. 

NOTE – Keeping the Under Bust seam aligned will ensure the adjustment lines are in the correct place.

Divide the Top Bust edge, on the Inner Bust Panel, into quarters.

Divide the Underarm edge, on the Outer Bust Panel, into quarters. 

Draw a line (1) across the bottom quarter markings across both panels, intersecting at the Bust Point.

Measure halfway across the line drawn (2) in step 1.3 on the Inner Bust Panel.

Draw a vertical line from the Top Bust edge to the Underbust edge.

Repeat step 2.1 to draw a line (3) on the Outer Bust Panel.

Starting at the Bust seam on the Inner Bust Panel, cut across the line (1) drawn in step 1.3, leaving a hinge at the Top Bust edge. Then cut up into the line (2) drawn in step 1.4, towards the Top Bust edge, leaving a hinge and cut down towards the Underbust edge leaving a hinge.

Starting the Bust seam on the Outer Bust Panel, cut across the line (1) drawn in step 1.3, leaving a hinge at the Underarm seam. Then cut up into the line (2) drawn in step 1.4, towards the Top Bust edge, leaving a hinge and cut down towards the Underbust edge leaving a hinge.

For cup sizes D-G follow steps 3.1 to 3.3. For bigger cup sizes follow steps 3.1 to 3.5.

Take the Inner Bust Panel and pivot the cut line at the Bust seam by the amount you need to increase by.

For example, if you are a G cup, you need to add 2 inches (as shown here).

Repeat step 3.1 for the Outer Bust Panel.

Draw a new smooth curved line along the Bust seam of both pattern pieces.

NOTE – As we are all different shapes, you may need to play around with the shaping of the pieces at this point to adjust them to your personal figure.

H-K CUP: Pivot the Inner Bust Panel vertical lines (2) adding ½ inch into the Top Bust and ½ inch into the Underbust.

Tape these cut lines in place.

Trace around the Top Bust and Underbust edges. 

Draw a smooth curve around the new Bust seam.

TIP – I highly recommended using a French Curve ruler to draw the new Bust seam line.

Repeat step 3.4 on the Outer Bust panel. 

NOTE – Check that you have added the same measurements into both bust panels.

Your FBA is complete! Use these new bust pattern pieces, with the Top Bust Panel piece, to make a muslin (a test garment out of inexpensive fabric) to check the fit.