Balconette vs. Foam Bra Cups: Which Should You Choose?
Bra cups are the essential component that gives a bra its shape and prevents show-through on the outer fabric. Without them, the cup collapses and loses its form entirely. There are two primary types: molded balconette bra cups (semi-spherical, designed for open necklines) and soft flat foam bra cups (used in everyday bras and the majority of styles). The right choice depends on your bra design, cup size, level of support required, and target customer. Here's a full breakdown.
How Balconette Bra Cups Differ from Foam Bra Cups
The key difference lies in shape and application.
Balconette bra cups. Molded semi-spherical cups with a pre-set shape. Firm, fixed structure, typically made from seamless nylon or a foam core with a nylon covering. Open at the top, designed for low-cut necklines, corset tops, and premium balconette-style bras. Must be sized precisely to the bust measurement (e.g., 70A–100D in EU sizing).
Foam bra cups. Soft, flat inserts made from polyurethane foam in various thicknesses. Suitable for standard bra styles, sports bras, and everyday basics. Universal fit — no exact sizing required. Cut to the shape of the bra cup pattern piece.
Balconette: molded, size-specific. Foam: soft, cut-to-fit for general construction.
The core distinction in a single sentence: balconette cups are for open-neckline bras with a defined shape; foam cups are for standard and sports styles.
Comparison Table
Parameter
Balconette 75B
Balconette 90B
Thin Foam
Push-Up Foam
Memory Foam
Seamless Molded
Shape
semi-sphere
semi-sphere
flat
flat base + thin top
semi-sphere
semi-sphere
Firmness
medium-firm
medium-firm
soft
firm at base
soft, shape-retaining
medium-firm
Push-Up Effect
moderate
strong
none
strong
moderate
moderate
Application
open-neckline bras, corset tops
full-cup / large-cup bras
everyday bras, sports bras
push-up bras
premium bras
seamless lingerie
Sizing
by cup letter, 70A–100D
70A–100D
universal
universal
by cup letter
by cup letter
Thickness
1–2 cm (⅜–¾ in)
1.5–2.5 cm (⅝–1 in)
0.5–1 cm (¼–⅜ in)
2–3 cm at base (¾–1¼ in)
1–1.5 cm (⅜–⅝ in)
0.5–1 cm (¼–⅜ in)
Wholesale Price (per pair, approx.)
budget entry-level
mid-range
lowest cost
low-mid
mid-premium
mid-premium
Balconette: open-neckline bras. Foam: everyday and sports styles. Push-up: lift and volume effect. Memory foam: premium segment.
Which Bra Cup Type Works Best for Each Style
Choosing by garment type.
Balconette bra (open neckline). Molded balconette bra cups only — semi-spherical profile. Must be sized exactly to the bust measurement. Typically nylon-covered or foam-core with antibacterial finish.
Push-up bra. Push-up foam bra cups with a 2–3 cm (¾–1¼ in) thick base and thin upper section. Creates a lifted, fuller appearance. Can be combined with balconette cups for enhanced effect.
Everyday full-coverage bra. Thin foam bra cups, 0.5–1 cm (¼–⅜ in). Prevent nipple show-through on the outer fabric and provide gentle shape without a rigid dome.
Sports bra. Soft foam bra cups, 0.5–1 cm (¼–⅜ in), or no cups at all. A firm molded structure restricts movement during high-impact activity. In sports bras, the priority is compression, not shape.
Swimwear with standard support. Water-resistant foam bra cups, 1–1.5 cm (⅜–⅝ in), or molded plastic cups. Must dry quickly and resist water absorption.
Teen and junior bras. Thin foam bra cups, 0.3–0.5 cm (⅛–¼ in), or no cups. Light, minimal coverage without pressure on developing breast tissue.
Maternity and nursing bras. No cups, or removable thin foam inserts. Must not obstruct feeding or compress breast tissue.
Corset top with balconette. Molded balconette bra cups are built into the upper section of the corset. Provide a structured, defined bust silhouette — ideal for eveningwear and performance costumes.
Premium lace bra. Memory foam bra cups, 1–1.5 cm (⅜–⅝ in). Soft, shape-retaining as they warm to body temperature, and resistant to crushing.
Seamless bra for fitted clothing. Seamless molded bra cups. No side seams or panel joins — perfect under fitted dresses and blouses.
For a full overview of lingerie notions and haberdashery, see our guide Lingerie Hardware & Notions.
Balconette Bra Cup Size Chart
Molded balconette bra cups must be matched precisely to the bust size. Sizing follows the standard EU bra convention — a band number (underbust circumference) paired with a cup letter: 70A, 75B, 80C, 85D, 90D, 100D, and so on.
70A–70B. Small bust, junior market, lightweight styles.
75A–75B. The most popular size for mainstream and mass-market production. The majority of bra styles are graded to 75B.
80A–80C. Average bust. Often requires slightly deeper cup depth.
85B–85D. Fuller bust. A well-suited size range for push-up styles.
90A–90D and above. Large bust. Typically requires premium series cups with reinforced support.
Important note. Customers generally know their cup size by letter. The bra cup must correspond exactly to the wearer's size and shape — a mismatch causes the cup to collapse inward or dig into the breast.
Materials: What to Look for in Bra Cups
Foam bra cups. Medium-density polyurethane foam with a nylon (polyamide) or polyester covering. Breathable and shape-retaining. For premium applications: memory foam with shape-recovery properties.
Molded balconette cups. Nylon outer shell with a 1–2 cm (⅜–¾ in) foam inner layer. Smooth surface finish, no visible seams.
Seamless molded cups. Solid polyurethane construction with surface coating. No seams, no side panels. Premium segment.
Thermal bra cups. Insulated cup with a foil layer inside. Retains body heat. Designed for winter lingerie and customers who feel the cold.
What to avoid. Cheap bare foam with no covering — it crumbles after 5–10 washes. Overly rigid plastic cups with no soft shell — they chafe against the skin. Any bra cups without skin-contact safety certification.
How Many Cups Per Garment
Standard notions requirement per finished garment.
Everyday bra: 1 pair of molded balconette or thin foam bra cups, sized to match the cup letter.
Push-up bra: 1 pair of push-up foam bra cups with a thickened base section.
Corset top with built-in cups: 1 pair of molded balconette cups in the corresponding size.
Swimwear with support: 1 pair of water-resistant molded plastic cups.
Sports bra: 1 pair of thin soft foam bra cups, 0.5–1 cm (¼–⅜ in), or no cups.
Plus-size / full-cup bra (D+): 1 pair of balconette cups in the corresponding letter (D, E, F) with reinforced support structure.
For production runs, allow a 5–10% buffer per size. When cutting across a full size range (70A, 75B, 80C, 85C, 90D), stock each size separately — they are not interchangeable.
Pricing: Wholesale vs. Retail
Retail (sold individually or in small quantities online). Molded balconette bra cups vary widely in price depending on size and quality. Thin foam cups are the most affordable option. Push-up cups sit in the mid range. Memory foam and seamless molded cups command the highest retail prices. As a general rule, expect retail pricing to be 3–5× wholesale cost.
Wholesale pricing (direct from supplier). Entry-level balconette cups in smaller band sizes (70–75) are the cheapest per pair. Mid-range sizes (75–85) cost more. Large-cup sizes (90–100) carry a further premium. Thin foam cups are the most cost-effective wholesale item. Push-up, memory foam, and seamless molded cups all sit progressively higher in wholesale cost.
For a small production run of 10 bras with balconette cups: source 10 pairs across the size range (70A, 75B, 80C, 85C, 90D — proportioned to your expected sales split). For larger batches of 50+ units, buy by full size runs to qualify for volume pricing.
Recommended Cups by Garment Type
Everyday bra in the most popular size, 75B, with an open neckline: white balconette bra cups, 75B. The go-to size for mainstream production runs.
Junior or lightweight bra styles in sizes 70–75A: white balconette bra cups, 70B. Light support for smaller bust sizes.
Bras in black fabrics or dark fitted garments: black balconette bra cups, 70B. Concealed inside dark fabric without show-through.
Full-cup or supportive bras for larger bust sizes (D–E), shaping and minimizer styles: white balconette bra cups, 90B. Reinforced support for a fuller bust.
Browse the full range in our Notions & Haberdashery and Lingerie Fabrics categories. Related guides: Lingerie Hardware & Notions, Lingerie Fabrics, Fabric for Underwear.
Common Mistakes When Selecting Bra Cups
Using 75B balconette cups for an 85D bust. The cup is far too small — the breast won't fit, and the cup collapses. Always size to the exact bust measurement.
Fitting rigid balconette cups into a sports bra. The firm molded structure restricts movement during high-impact activity. Sports bras need soft foam cups or no cups at all.
Constructing a full-cup bra for a larger bust using only thin foam without additional support. For D+ cup sizes, thin foam alone is insufficient — the cup will sag. Use molded balconette cups with reinforced support.
Buying uncoated bare foam cups. Raw foam with no covering crumbles after just 5–10 washes, leaving white residue inside the garment. Always specify nylon-covered foam bra cups.
Cutting the bra cup pattern without accounting for the cup insert size. The sewn cup must match the cup insert precisely. If the cup is cut too large, the insert shifts sideways and loses its shape.
Using standard foam bra cups in swimwear. Regular foam absorbs water and takes a long time to dry. For swimwear, always use water-resistant molded plastic or hydrophobic-coated foam cups.
Confusing band size with cup size. A 75B and a 75C are different cup depths — they are not the same insert. Never mix up the band number (circumference) with the cup letter (volume).
Frequently Asked Questions
What are molded balconette bra cups? Pre-shaped semi-spherical cups with a fixed form. Firm structure made from nylon or covered foam. Used in open-neckline bras, corset tops, and premium styles.
What is the difference between balconette and foam bra cups? Balconette cups are molded, semi-spherical, and designed for open necklines and structured shape. Foam cups are soft, flat, and suitable for standard closed bras and sportswear.
How do push-up bra cups work? Push-up foam bra cups have a 2–3 cm (¾–1¼ in) thick base that tapers toward the top. This creates a lifted, fuller appearance. They can be combined with balconette cups in sizes 75–85 for greater effect.
What cups are best for a sports bra? Thin soft foam bra cups (0.5–1 cm / ¼–⅜ in) or no cups at all. Rigid balconette cups impede movement during exercise. A sports bra is built around compression, not shaping.
How do I choose the right size? Match to EU bra sizing: 70A, 75B, 80C, 85D, and so on. The most common size for mainstream production is 75B. For larger busts (D+), use balconette cups in the 85–100 band range. Your customer should know their bra size.
What makes memory foam bra cups different? Memory foam is a premium polyurethane foam that softens and conforms to the body's shape with heat, then returns to its original form. More expensive than standard foam, but significantly more comfortable in high-end bra styles.
What type of bra cups should I use in swimwear? Water-resistant molded plastic cups or foam cups with a hydrophobic coating. Standard foam cups absorb water and dry very slowly — avoid them in swimwear construction.
How many pairs should I order per production run? One pair per garment. If you are cutting across a full size range (70A, 75B, 80C, 85C, 90D), order each size in proportion to your expected sales. As a rule of thumb, 75B typically accounts for 30–40% of a standard run.
Where do I source bra cups wholesale? Turkish and Chinese direct manufacturers are the most common wholesale sources. For premium quality, look to Italian distributors. Minimum order quantities typically start at 50 pairs per size.
Are balconette cups suitable for teen bras? Rigid molded balconette cups are not recommended for developing breast tissue. For juniors, opt for thin soft foam bra cups or bras with no cup inserts at all.