Latex balloons may be inflated with either air or helium. Because latex is a porous material, the gas (helium or air) molecules pass through the surface, eventually causing the balloon to deflate or descend.
The size of your helium filled balloon determines how much weight it can lift e.g ribbons and tassels. If your your helium balloon is sagging, remove any added decorations and watch it fly high again.
When air-inflated, latex balloons stay inflated considerably longer than those inflated with helium because air molecules are larger and slower moving than helium molecules, so air doesn't escape as quickly as helium.
Float times can be extended by treating latex balloons with Ultra HI-FLOAT.
TEMPERATURE & HELIUM
Helium-inflated balloons are affected by extreme temperatures and humidity.
For example, moving helium-filled balloons from an air-conditioned room to one that's not or to the outdoors on a warm or hot day will result in the balloon expanding.
LATEX BALLOON OXIDATION
Latex balloons can become covered with a velvet finish when atmospheric conditions change, such as in high humidity or when exposed to sunlight. This velvet finish is the result of oxidation, the first step in the bio-degradation (or natural breakdown) of the natural latex. To decrease the possibility of oxidation, cover balloons with a plastic bag, especially if they will be exposed for any length of time. When inflating large quantities of balloons for decorating, many professionals recommend inflating the balloons on-site to try and avoid oxidation when the balloons are transferred for the store to the site, especially when moving the balloons in and out of air-conditioned facilities.
The use of products such as HI-FLOAT or Balloon Shine to the exterior of the balloon can assist in slowing the process of oxidation.