I tried sealing it with air in, and with water. I tried wetting the seal first, I tried it dry. I never was able to get any of the three of them to seal properly. I also ordered the small cup, and it wouldn't seal either. Very disappointed. Also, it's so thick it takes up way too much room in the lunch bag, and while they do stand up, if you should want to lay it on its side to place your sandwich on, the bottom sticks up and your sandwich slides off. ( I returned all of these and purchased another brand, which are awesome.)

AWFUL!!! Bought for my daughter in law, friend and myself---and we are ALL disappointed!! THEY DO NOT SEAL--SAVE YOUR MONEY!!

I really wanted to love this product but it does not work as advertised. The seal on this product is very weak and inconsistent. I believe it’s because the the silicone is too thick which makes it too rigid, and when you zip the top closed, the stiffness/thickness prevents it from staying completely closed. Some other silicone bags I use are able to keep cut apples from oxidizing/turning brown for a few hours and I assumed this product would do the same but they failed miserably. The seal is extremely uneven and the edges do not stay closed. As a result, food can not stay fresh. The other design flaw is the shape. Many of the photos in their ads show contents filled to the brim of the container but if you try to close it, the contents at the top are crushed and smashed. As a result, you can’t fill the constrainers more than halfway unless you want bruised fruit or crushed crackers/cereal etc...

I wanted to love these and was excited to use them. I hand washed them just to make sure they would work correctly. This was a waste. They leaked and wouldn’t seal all the way. They food I alarm was dried out the very next day. Gave it another chance and then the same thing happened. Hoping to try a another brand as I like the concept of being more economically friend!

It keep opens on the edge while in the bag.