The easiest way to see why direct label conversion fails is to hold the measurements constant. These examples use overlapping published ranges and BRABAR's published band/cup method to show how different the labels can look.
| Underbust | Bust | Bleuet | Yellowberry core | BRABAR method |
|---|---|---|---|---|
| 28 in | 29–30 in | 12 | S | 28A–28B |
| 30 in | 31–32 in | 14 | M | 30A–30B |
| 32 in | 33–34 in | 16 | L | 32A–32B |
| 34 in | 35–36 in | 18 | XL | 34A–34B |
| 36 in | 37–38 in | 20 | Plus 1 | 36A–36B |
| 38 in | 39–40 in | 22 | Plus 2 | 38A–38B |
The BRABAR column shows the result range for a bust difference of one to two inches. It does not claim every BRABAR product is stocked in every displayed size.
What this demonstrates
A 32-inch underbust with a 33–34-inch bust can sit inside Bleuet size 16, Yellowberry L in the core cotton chart, and produce approximately 32A–32B under BRABAR's measurement method. None of those labels can be safely inferred from either of the others.
Style families can change the answer too
Yellowberry's seamless/Tulip family uses grouped labels such as XS/S, S/M and L/XL rather than the seven-label core chart. Bleuet also identifies style-specific exceptions. This is why the database stores brand + sizing family + measurement range, not just brand + label.