I went looking for Gerber breast milk bags and found both Gerber and a brand called Lansinoh. See enclosed photo. I ended up buying the Lansinoh breast milk bags as they had a double zipper and the box said "the thickest bag available".

I don't have any experience with the Gerber bags. However, the Lansinoh also have a built-in pour spout.

So...does anyone make larger bags? ...or all they all 6oz?