Iris Bralette Tutorial: Moving the Vertical Seam

For the best fit on the Iris Bralette, you will want the vertical seam to fall in line with the apex.

What is the apex?

The apex is the fullest part of the bust, usually where the nipple lies.  In the photo above, you can see that the vertical seam aligns with the fullest part of the bust, and also aligns with the vertical seam on the dress form.  

In the image to the left, you can see that the vertical seam is too far outwards, and does not align with the apex.  Breast shapes can vary, so it may be necessary to move the vertical seam closer to the center front to align with the apex.  ​

How to Alter the Pattern

To begin, measure the distance from the vertical seam to the apex.  This is how far you will need to move the seam. For this exercise, let's say we need to move the seam 1/2".

Now you will need the inner cup and outer cup pattern pieces.  Align the pieces so that the  apex notches are level.

Add 1/2" to the vertical line on the outer cup, and remove 1/2" from the vertical line on the inner cup.  Keep the top and bottom of the cup level with the original lines. Mark the new apex notches.

Now you need to check your work to make sure the seam lines are the same length.  It is best to measure them along the actual seam line, and not the cut edges.  Mark in your 1/4" seam allowances. 

You can either measure each seam line separately with a flexible measuring tape, or you can "walk" your pattern pieces. 

​Adjust the curves slightly, if necessary, so that the seam lengths match.  Shown to the left, the pattern pieces are resting on top of each other, with the yellow indicating the seam allowance areas.

Last, you will need to move the notch on the cradle piece 1/2" towards the center front so that it will align with the new cup seam.

Now, when you sew up your new pattern pieces, the seam line should align with the apex.

Happy Sewing!