Latex is a semi-porous material. Balloons filled with helium will deflate faster where the temperature is hotter or the altitude is higher. The helium (and even air) in full sun will expand and may pop the balloon if filled completely and due to heat will deflate quicker. Balloons last longest in indoor cool environments. Darker colored balloons, metallic and iridescent balloons will last longer due to having more pigment which retards gas loss. There is also a product which can be sprayed into helium filled balloons before they are inflated to make them last longer but we feel this is a lot of work for most uses. Balloons filled with air last much much longer than helium filled balloons because helium is a thinner gas.
We did comparison tests with our balloons and found them to be of very comparable quality. We experienced a blowup breakage rate of less than 1%. Floating times were done inside at sea level. We found that some top brand standard colors were very slightly brighter with respect to some colors but not significant in our opinion. Because we sell direct we can offer these quality balloons at this great price.
NEED HELIUM? We have found that the best source of helium is your local welding supply store where you can get a rental tank.