The Right Way to Fill Mylar Balloons

How to Properly Fill Mylar (Foil) Balloons

You should only fill mylar (foil) balloons to about 80% or 85% of their maximum capacity to prevent them from popping. Mylar does not stretch like latex; Over-inflating creates too much pressure on the seams, causing them to burst or leak.

What does the best result look like?

The balloon should look full and smooth, but you should still be able to press your fingers gently into the edges or see slight wrinkles along the sealed seams