The band: the anchor test
The band does most of the work in any construction, so the checks start there. A fitted band sits level all the way round - front and back at the same height - and passes the two-finger test: two fingers slide under the band at the side, snugly but without a struggle. When the wearer raises both arms above the head, the band stays down against the ribcage; if it lifts or slides round the back, the anchor has failed.
Riding up has two possible sources and they call for different responses. If the band is comfortable but climbs, it is simply too large - a band step down with the corresponding cup adjustment along the sister-size diagonal is the answer. If the band is snug on the day it climbs, the elastic lacks recovery: it stretches to its working extension and stays there. That is a material problem, not a size problem, and it is caught in sampling by checking recovery after repeated stretch rather than on a fresh garment. Both failure paths are detailed in the band tightness note and the riding-up note.
The cups: containment without gaping
A fitted cup holds all of the breast tissue - front, side and underneath - without empty space at the top edge and without spillage at the neckline or under the arm. Three checks cover it. The wire at the bottom of the cup follows the crease where the breast meets the chest wall, sitting on the ribcage rather than on tissue. The top edge of the cup lies flat against the breast; a gap that a flat hand can slide into means the cup is too deep or the style is wrong for the shape. And nothing bulges: tissue above the cup edge or pressing out at the underarm means the volume is short by a step or the wire is too short for the root.
Gaping deserves a second look because consumers routinely misread it. A top gap in an upright posture that closes when the wearer leans forward is often a shape mismatch, not a size error - the cup is drafted for more projection than the wearer has. The fix is a different style within the same size, which is why the desk treats style family and size as separate axes in every fit review. The dedicated causes and fixes are in the cup gapping note.
The straps: fine-tuning, not carrying
Straps are adjustment surfaces, not load paths. In a fitted bra the band carries most of the weight and the straps hold the cup against the body - light contact, no grooves in the shoulder at the end of a day, no constant slipping. Digging straps usually indict the band first: when the band is loose the cups drop, and the wearer shortens the straps to compensate, transferring load onto a component that was never dimensioned for it. The sequence to check is therefore band first, strap width second; the construction side of that trade-off is in the strap digging note.
Slipping has its own geometry. Straps set wide - as on some balconette cuts - fall off sloped shoulders regardless of adjustment, which is a strap placement issue rather than a tightness issue. A convertible or racerback option solves it mechanically by pulling the anchor points inward, which is why the sports constructions on this site offer it as a variant.
Strap construction scales with the size grid even when the fit is right. Narrow elastic that disappears on a 32B leaves pressure marks on a 38DD, so spec sheets typically widen the strap above a defined cup step and reduce its stretch ratio at the same time. Attachment points matter as much as width: a strap anchored close to the cup edge twists under load, while one anchored into the wing line stays flat. These are component decisions, and they belong in the spec sheet rather than in the fit session, which is why fit notes that keep saying wider straps are a signal to re-open the construction section of the program.
The movement tests
Static checks happen standing in front of a mirror. Dynamic checks take thirty seconds and predict the daily-wear report better:
- Raise both arms overhead. The band stays down; the cups stay filled; nothing escapes at the edges.
- Lean forward. Tissue settles into the cups without spilling, and the wire keeps its track around the root.
- Sit and reach. The band flexes with the ribcage instead of pressing or shifting, and the hooks stay comfortable against the back.
- Button a close-fitting top over it. Smoothness at the cup edge and the back is what the wearer actually judges.
A bra that passes all four is fitted. One that fails exactly one tells the fitter which component to change, which is the real value of the checklist: it converts a vague complaint into a parameter.
From fit notes to spec changes
For a buying desk the same signs run in two directions: outward as consumer guidance, inward as inspection criteria. The table below maps the common symptoms to their spec-level responses, which is the format fit-session notes take when they come back from a sample round.
| Symptom | Likely cause | Spec-level fix |
|---|---|---|
| Band rides up | Band too large, or elastic with low recovery | Band step down on the diagonal, or higher-recovery elastic |
| Straps dig | Band loose, load shifted to straps | Band correction first; wider strap as second step |
| Straps slip | Strap set too wide for the shoulder | Narrower strap set or convertible back option |
| Tissue spills at the edge | Cup volume or wire length short | Cup step up; re-grade wire with the cup |
| Top cup gaps | Cup drafted for more projection | Style change within the same size |
| Wire presses at the side | Wire curvature mismatched to the cup | Wire grade reviewed per size run |
Fit sessions test a size run, not a single sample, because every one of these symptoms intensifies toward the edges of the grid. Sampling for catalog constructions typically runs one to three weeks, with fit blocks confirmed per program; the reference timings are on MOQ and lead time and the fit-session scope belongs in the first brief through the quote form. The sizing and fit guide ties the checks into the wider documentation set.