Bust Cups Bust Cups Bust Cups Bust Cups (17 ratings) Bust cups suitable for bra making and swim wear. £4.00 Out of stock. These bust cups work perfectly with our Belle swimming costume pattern to provide additional support and structure. Read the Blog post to find out how to add them to you make. These replacement cups can also be used in sports bras, seamless bras and dresses with built in bra pads. Cups can be trimmed to shape and are machine washable at 40°.