12ft Birthday Boy Prism Banner. Put up a fun and adorable greeting with our Prismatic Foil “Birthday Boy” Banner. 1 Birthday Banner – 12 ft. This prismatic banner features a blue “Birthday Boy” headline on a silver background with colorful designs. This disposable prismatic banner is perfect for celebrating fun birthday parties. Made of durable foil material, this prismatic banner is very eye catching with high quality prints. This product is easy to assemble, install, and can be stored and re-used.