Bra

Fashion Academy · Garment anatomy

The Bra

A bra is a close-fitting support garment built from small, highly engineered components that must work together around the whole torso. This guide uses a classic underwired bra with two-piece cups to show how shaping, support, adjustment and comfort are distributed through the garment.

Black-and-white technical flat of a classic underwired bra shown from the front and back — This is one common construction rather than a universal formula. Wireless bras, moulded cups, bralettes and sports bras may remove the wire, change the cup architecture or distribute support through compression and wider panels.

Read the construction

A bra is a system, not a pair of cups with straps attached. The band supplies much of the support, the cups create and contain volume, and the bridge, wires, elastics and hardware keep those forces controlled and adjustable.

Upper cup

The upper cup forms the section between the main cup seam and the neckline. It controls coverage, contains the upper breast tissue and connects the cup to the strap. Its edge may use fold-over elastic, decorative elastic or a stabilised fabric finish, depending on how much stretch the design permits. A stable upper cup gives a firm shape, while controlled stretch can adapt to small changes in volume. The pattern must meet the lower cup smoothly without sharp transitions. If the upper edge cuts in, gaps or collapses, the cause may be its shape, material stretch or the relationship between cup and strap—not simply the labelled size.

Lower cup

The lower cup carries much of the breast weight and creates projection away from the body. In this example it is divided by a vertical seam, allowing flat fabric pieces to form a rounded three-dimensional shape. Materials are often firm or lined to resist downward stretch. The lower cup must fit accurately into the cradle and follow the intended wire line without puckering. Small changes to its height, width or seam curve noticeably alter lift and volume. During sampling, inspect whether the tissue sits fully inside the cup and whether the base of the cup remains anchored rather than being pushed down or away from the body.

Cup seam

The cup seam joins shaped panels and turns two-dimensional fabric into volume. Its direction also influences the visual and structural result: vertical seams tend to support lift, horizontal seams can control depth, and diagonal seams distribute shaping differently. Seam lengths must match precisely even though the curves may look unlike one another when flat. Use accurate notches and avoid stretching one edge to force a match. The finished allowance may be pressed, enclosed or covered with seam tape according to the fabric. A smooth seam should form a continuous curve without points, ridges or a flattened area at the join.

Neckline edge

The neckline edge runs from the bridge towards the strap and defines the upper line of the cup. It must contain the breast without cutting in or standing away. Some designs stabilise this edge almost completely; others add narrow elastic for gentle recovery. The tension has to be applied evenly because a few millimetres of extra stretch can change how the cup sits. The edge shape works together with cup volume and strap position, so gaping is not always fixed by tightening the strap. On delicate fabrics, clean stitching and a soft finish matter because this edge remains visible and sits directly against sensitive skin.

Underarm edge

The underarm edge connects the outer cup and wing, curving beneath the arm towards the back. It needs enough height to contain tissue and stabilise the side, but not so much that it rubs or restricts movement. Elastic is usually applied with controlled tension so the edge returns to the body without digging in. The fabric and elastic must stretch together smoothly; too much tension creates a tight ridge, while too little causes gaping. During fitting, check the position with the arms relaxed and moving. Discomfort here may come from cup width, wing height, wire length or elastic tension rather than the edge alone.

Underwire and wire channel

The underwire sits inside a strong fabric channel sewn along the lower edge of each cup. It supports the cup at its root and transfers load into the frame and band. The wire must match the intended breast-root shape and cup construction; it should surround the tissue without resting on it. Channel length includes safe clearance at both ends so the wire cannot pierce the fabric during wear. Stitching must remain parallel and secure without catching the wire. Not every bra needs one: wireless styles use seaming, fabric stability, wider bands or internal slings to create support by different means.

Centre-front bridge

The bridge, often called the gore, joins the cups at centre front and helps anchor the bra against the body. Its width and height depend on cup spacing, wire shape and neckline design. In a well-fitted underwired bra, the bridge generally sits close to the sternum without pressing painfully. Stable fabric prevents it from stretching apart under tension, and its upper edge must be finished without creating bulk. A bridge that floats can indicate insufficient cup volume, an unsuitable wire or a shape mismatch; narrowing the bridge alone is not always the correct answer. Accurate symmetry here is essential because every front component meets around it.

Cradle or front frame

The cradle is the front frame surrounding the lower cups and bridge. It holds the wire channels in position and connects them to the wings and underband. Because it controls the relationship between two cups, it is usually made from stable material or reinforced to limit stretch. The cup opening in the cradle must match the wire line accurately, including seam allowances and balance marks. If the frame stretches or distorts, the wires can spread and the cup shape changes. Some bras use a partial frame or no separate cradle, but a full-frame construction gives beginners a clear way to understand how support is distributed across the front.

Underband elastic

The underband elastic finishes the lower edge and plays a major role in anchoring the bra around the torso. It is shorter than the fabric edge and applied under measured tension so it stretches comfortably in wear and recovers afterwards. The first stitching pass secures the elastic, then it is turned and stitched again to enclose the raw edge. Tension must be consistent; over-stretching creates ripples or a harsh grip, while insufficient tension allows the band to ride up. Elastic width, firmness and recovery should suit the garment size and support level. Always test the elastic after repeated stretch and washing, not only when new.

Shoulder straps

The shoulder straps stabilise the upper cups and allow the neckline position to be adjusted, but they should not carry the entire weight of the garment. Their width and elasticity affect comfort, especially in larger sizes. The front attachment point helps control cup support and neckline tension, while the back position influences whether straps remain on the shoulders. Straps may be fully elastic, partly stabilised or constructed from fabric with an elastic section. During fitting, adjust them enough to remove slack without pulling the back band upwards or forcing the cups into the body. Reinforce attachment points because repeated tension concentrates stress there.

Rings and sliders

Rings connect straps to the cup or back band, while sliders change the usable strap length. Their internal width must match the strap so it moves smoothly without twisting or slipping. Hardware should be strong, smooth-edged and compatible with the garment’s laundering requirements. The strap is threaded through the slider in a specific path that locks its adjustment under tension; incorrect threading can make it loosen during wear. Rings also need enough space to pivot as the body moves. In production, check that both straps are assembled as mirror images and that joins are securely stitched without catching or distorting the elastic.

Wing

The wing extends from the outer cup and cradle around the side of the torso. It contains the side area, transfers tension towards the back closure and helps keep the wires anchored. Power mesh is common because it stretches around the body while providing firm recovery. The direction of greatest stretch is deliberately placed around the torso, not vertically. Wing height affects support and underarm comfort, and its upper and lower edges are controlled by elastics. A wing that is too stretchy can reduce stability; one that is too rigid may feel restrictive. Its pattern must also account for the reduction created when the elastics are applied.

Side seam

The side seam joins the stable front cradle to the stretchier wing, marking a transition between different materials and functions. It must withstand constant tension without becoming bulky or abrasive. Seam allowances may be enclosed, overlocked or covered depending on the construction and fabric. Precise matching keeps the underarm and lower edges continuous so the elastics can be applied smoothly. Some designs incorporate a side bone near this seam to prevent rolling, although it must be positioned and cushioned carefully. The seam angle also influences the direction of pull from front to back, so it is part of the support geometry rather than merely an assembly line.

Back band

The back band continues the wings towards the closure and supplies much of the garment’s circumferential support. It should sit level around the body, firm enough to anchor the front but comfortable through breathing and movement. A band that rides up is often too loose, excessively stretchy or being pulled by over-tightened straps. Its top and bottom elastics may use different tension and widths to control the edge. The band tapers to fit the closure height, and the strap attachment must be reinforced. Designers grade band length and strength with size because the same material behaviour will not provide identical support across every range.

Hook-and-eye closure

The hook-and-eye closure opens the band for dressing and provides several adjustment positions as the elastic relaxes over time. The hook piece and eye piece are sewn to opposite back ends, with soft edges facing the skin. Their height must match the finished band and the number of hook rows specified by the support level. The newest bra is generally fitted on the loosest comfortable setting, leaving tighter positions available later. Alignment is critical so the upper and lower band edges remain level when fastened. Stitching must secure every layer without leaving hard corners or exposed hook tape against the body.

Your cart is empty

Your cart

Estimated total

Bra