The main concept of air pressure within a balloon that is critical to know is that air pressures "attempt" to even out. With all of the bouncing in opposition to the balloon wall (both inside and exterior) there will be a particular amount of enlargement/contraction. As air pressure by itself https://helium-balloons-dubai-mar70356.theideasblog.com/37063342/the-ultimate-guide-to-festival-balloon-supply-dubai