You are in the home stretch of fitting your custom made bra and you just need a little more room in the cup. Key Indicator? There is a bit of a “flat spot” at the base of the bra cup while the upper cup looks a bit small or tight.
If the rest of the bra fits well, a flat spot at the base of the cup is generally the result of insufficient volume which prevents the breasts from fully sinking into the cups. If the breasts can not drop to the base of the cup, the breast is forced upwards which makes the upper cup look too small. Often the answer is to go up a cup size, but if you tried going up a cup size only to find it too large, this bra sewing tutorial may be the solution for you!
To add to the lower cup of the bra we are going to split the lower cup and add volume along the new seam line. I am going to use the lower cup from the Marlborough bra sewing pattern to show this alteration step-by-step:
- First you will need to determine how much extra room you need to add to the cup. You can do this by examining the dimensions of the flat spot at the very base of the cup because that is roughly the amount of volume that you need to add. Note that I do not recommend this alteration if you need to add more than ¾”. If that is the case, you really should go up a cup size.
- Divide the amount of the lower cup increase by 2. In this example I am adding ½” which when divided by 2 equals ¼”. This is the amount you will be increasing each lower cup.
- To split the lower cup, draw a line from the apex point to the base of the cup. This line is drawn parallel to the stretch arrow. (Note: if your lower cup does not have an apex point marking, add one!*)
- Measure from seam line to seam line to find the mid point of the line you drew in step 3. Mark this point.
- Cut along the line you drew in step 3 and tape the pattern pieces to pattern paper so you can expand along the cut line.
- From the center point marking you made in step 4, measure out the amount of the increase you calculated in step 2. In this example I am using ¼”.
- Draw in a new seam line. Remember, all pattern changes are made from the seam line, not the cutting line!
- Add ¼” seam allowance and draw in a new cutting line. Then trace over the seam and cutting lines from one side to the other – so you know they match – and extend the mid point line from step 4 to be the construction joining notch.
9. Finally, mark the revised lower cup pieces so you understand their directionality and placement in the final bra.
Did you know that altering the cups is actually the last fitting adjustment you should make? If you want to learn more about pattern alterations for bra fitting get my book where I take you through my systematic fitting process and the most common pattern adjustments!
*The A to DD Marlborough size range does not have an apex mark on the lower cup. It does have an apex marking on the upper cup. To create the apex marking on the lower cup simply walk the seams to find the corresponding position on the lower cup and mark it!
