One 18 inch Butterfly Foil Balloon. No party is complete without balloons, and this cute square foil balloon is perfect to help celebrate a butterfly themed birthday party. Add it to a solid color latex balloon bouquet, or tie to the mailbox to help guide guests to the party area. At such an affordable price, you could even buy one for every party guest, and attach it to their treat bags as a thank you for coming to the party. Birthday Direct has all the best party supplies at the best low discount prices.