Polka Dots are a popular way to theme a birthday party and these 18 inch Birthday Big Polka Dots foil balloons will be ideal for doing just that! They are printed allover with big, colourful polka dots with ‘Happy Birthday’ so make brilliant birthday decorations. You can inflate foil balloons with air or helium but they do require helium to float. Once inflated with helium they will float for days. Supplied un-inflated.