07/31/2026
Fit Tip Friday: The Sister Size Trap for Fuller Figures 🎀
If you have a fuller bust, you know the frustration: you find a bra you love, but the band is too tight. The salesperson tells you, "No problem! Just try the next band size up and go down a cup letter. It’s a Sister Size—the volume is exactly the same!".
The Reality Check: 🚩 For women with larger busts, this "shortcut" is often where the fit falls apart. While a 42D, 40DD, and 38E (DDD) might technically hold a similar volume of tissue, they are designed for completely different frames.
Actually, while 85% of all women wear the wrong bra size, for those of us in larger size ranges, that number approaches 100%. Here is why the "Sister Size" myth fails the fuller figure:
The Vanishing Support: A snug, level band should provide the vast majority of your support—not the straps. When you move up to a larger band size just to get more room, you lose that essential anchor.
The Riding Band: If your back band is riding up toward your shoulder blades, it means the band is too large, not that the cups are too small.
Moving to a larger sister size only makes this worse, leading to slipping straps and zero lift.
The Rounding Problem: Retail manufacturers often round up sizing metrics, which results in cups that gap and bands that lack the necessary tension to support a heavier bust.
The Solution: B.C.D. & HH plus Powerbars ✨ We don't rely on generic letters. We use the science of B.C.D. (Bottom Cup Depth). By measuring from your apex (the highest point) directly to your wire line, and the HH across the breast we ensure the cup is deep enough for your unique projection.
For larger busts, we also utilize the Powerbar—a side cup reinforcement designed specifically to push breast tissue forward and prevent "East-West" projection.
The Expert Fit Check: The Bridge & IMF 🛠️ Your bra should be a masterpiece of design. For true support, the Center Bridge should tack firmly against your chest wall with no gapping. If it does not it then there are two reasons as to why this is. 1.the wire isnt the correct size 2. the cup needs more inner fullness.
It should sit perfectly in your I.M.F. (the crease where the breast meets the ribcage) to ensure the wires are doing their job without sitting on breast tissue.
Progress, Not Perfection 🌸 If you’ve spent years struggling with "shape mismatches" or painful wires, don't be discouraged. Custom bras are built for your body, not a size chart.
Join our Community Circle! 🧵 Have you ever been "sister sized" into a band that was way too big? How did it affect your comfort? Share your story below and let’s help you find the support you deserve!
