I want to keep the balloon. How to raise balloons in summer?

It's easy to inflate a balloon. It's ok to inflate quickly at first, but in the later stage, the rubber of the balloon will become translucent because it becomes thinner and thinner. How transparent will the balloon be if it is inflated to the limit? Because of different materials, the expansion amount, ductility and shrinkage are also different. Full of air, if the air inlet is sealed, it can last about 15 days. Sometimes it lasts longer, depending on the temperature.