Simplisse Breastmilk Storage Bags, 25 Pack

These bags are great for freezing! Just lay them flat in your freezer and they freeze into perfect little "bricks." I tried doing the same with other bags and they don't freeze as flat or hold as much milk. These bags are also made of a thick plastic and have a double zip closure to make sure it's all sealed in.

These storage bags are a little pricey, but the material is thicker/stronger than the Lansinoh bags (which I had a leakage problem with) and it has the double closure (which the Medela bags do not). The labels are easy to mark and they stand upright and the measurements are pretty accurate. I use these with the first years milk storage organizer and it works great.

These bags seem nicer and sturdier than the Lansinoh bags. The Simplisse plastic is thicker and the bags don't plop over (unlike Lansinoh). I have not tried to defrost them, yet, however, so I don't know if there's any issue with leaking. Only cons are the higher price and that it's a bit harder to tear the seam on top as there's a little curve on the sides. First couple of bags I ripped a bit too much but thankfully they were still usable.