Why moulded cups fit differently
A fabric cup stretches and settles around you. A moulded cup is heat-formed foam with a fixed curve. Your breast has to match that curve, or there will be a gap somewhere or pressure somewhere.
So in T-shirt bras, two things matter more than usual: getting the cup size exact, and finding a mould whose shape is close to yours.
Which size to try
- Start with your usual size.
- Take the next cup up as well. With no give in the foam, a cup that is very slightly small will cut in at the edge, and a ridge shows clearly through a thin top.
- Keep the band the same. If you change the band, change the cup the other way to match. See the sister size chart.
How it should fit
- The cup edge lies flat against you all the way along, with no ridge and no gap.
- The centre panel rests on your breastbone.
- The wire sits in the crease under the breast, not below it.
- Under a fitted T-shirt, the outline is one smooth curve.
Check these after a scoop and swoop, and look in the mirror from the side.
Reading the problems
| What you see | Meaning | Try |
|---|---|---|
| Ridge at the edge, centre panel lifting | Cup too small | Cup up |
| Loose all over, centre flat | Cup too big | Cup down |
| Gap at the top, fits at the wire | Less upper fullness than the mould | Plunge or balconette T-shirt bra |
| Gap at the top, wire sitting low, centre lifting | Cup too shallow for a projected shape | Spacer or seamed smooth bra |
| Dent or wrinkle at the tip | Cup deeper than you | A shallower mould or a half-cup |
| One cup gapes | Uneven sides | Fit the larger side; add an insert |
The full reasoning is in why your bra cups are gaping.
If moulded cups never fit you
Some shapes rarely match a standard mould: very projected breasts, conical shapes, soft tissue with little upper fullness, and many busts above about a G cup. There are alternatives that still give a smooth finish.
- Spacer bras. A thin, flexible knitted foam that shapes to you.
- Smooth seamed bras. Unlined cups with flat or bonded seams and a plain fabric, which show very little under clothes.
- Lightly lined bras with a stretch upper section.
- Non-wired moulded bras in soft foam, which flex more than wired ones.
Choosing a mould for your shape
- Shallow or wide: most standard T-shirt bras suit you. See best bras for shallow breasts.
- Full on bottom: choose a plunge or balconette cut over full coverage.
- Full on top: choose a cup with a soft or slightly stretchy edge.
- Close set: choose a plunge T-shirt bra with a low centre.
Care
Moulded cups dent permanently if folded. Store them stacked one inside the next, never with one cup pushed into the other, and wash them by hand or in a structured wash bag. See how to store bras.
Frequently asked questions
Should I size up in a T-shirt bra?
Sometimes. Moulded cups have no stretch, so if you are between sizes or spill slightly at the edge, the next cup up usually fits better. If the cup gapes while the wire feels right, the answer is a different shape, not a different size.
Why does my T-shirt bra gape at the top?
A moulded cup is a fixed dome. If you have less fullness above the nipple, or your breasts are more projected or more conical than the mould, the upper cup has nothing to fill it.
Is a T-shirt bra the same as a padded bra?
Not quite. A T-shirt bra has a smooth, seamless cup, usually made of thin moulded foam to hide the outline of the nipple. It is lightly lined and does not add size. A padded or push-up bra has thicker foam intended to add shape.
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