TUTORIAL - How to Alter the Bottom Cup Depth of the Kanon Bustier Dress Pattern

Learn how to alter the Bottom Cup Depth (vertical length) while keeping the Horizontal Hemisphere (horizontal length) of a curved 3 piece bra cup! While this tutorial is tailored for the Kanon Bustier Dress Pattern, the methodology can be used for ANY bustier pattern with a similar seamlines. That said, this is ONE method of increasing/decreasing the bottom cup depth (BCD) of the cups in detail and utilizing the “Layers” option in Adobe Reader (FREE). For a primer using Layers in Adobe Reader, click [HERE]

Here’s a sample of someone’s measurements. Lets call her Heidi.

Dress Size = 12 (highbust*, waist and hip)

Horizontal Hemisphere (HH) = 13.5” (34.4 cm)

Bottom Cup Depth (BCD) = 5.8” (14.7cm")

Since cup volume is determined by the HH measurement, we want to begin with the cup size that matches then adjust the BCD accordingly.

This means Heidi needs the volume of the larger HH (size 14) but a shorter BCD (size 12). We can accommodate that by reducing the BCD of the Size 14 G/H cup so it matches the BCD of the Size 12 G/H cup.

Larger Cup Size and Smaller BCD

Maintain cup width (HH) and shorten bottom cup height (BCD).

Start by circling the corner of the smaller BCD and the corner of the larger size [blue]. Then draw a gently curved line connecting the two corners from the same pattern piece [red]. We want to maintain the width (Horizontal Hemisphere) while shortening the height (Bottom Cup Depth). If your adjusted pattern piece has the same width but is a little shorter, you’re done!

Smaller Cup Size and Larger BCD

Maintain cup width (HH) and extend bottom cup height (BCD).

Start by circling the corner of the larger BCD and the corner of the smaller size [blue]. Then draw a gently curved line connecting the two corners from the same pattern piece [red]. We want to maintain the width (Horizontal Hemisphere) while lengthening the height (Bottom Cup Depth). If your adjusted pattern piece has the same width but is a little taller, you’re done!