Underwire bras provide support because the wire is a “frame” that goes under your breast. If the wire fits correctly (outside of breast tissue), the band is snug and anchors (not too tight, not too loose), and the cup encompasses breast tissue (no gapping, no spilling), the underwire bra will be supportive and comfortable. The wire will not dig or poke. Discomfort, broken wires, and bowing in the center indicate the underwire bra does not fit. A great fit is imperative for the comfort of an underwire bra.

Support and comfort, in both underwire and wireless bras, is also affected by fabrication. Stronger fabrics hold more and provide more support. Soft, stretchy fabrics are more relaxed and feel comfy. Underwire and wireless styles are available in a variety of these fabrications.