Lansinoh Breast Milk Storage Bags - 50 Count | BPA-Free, Pre-Sterilized, Leak-Proof | Perfect for Pumping, Freezing & Organizing Breast Milk

I love these breast milk storage bags. I haven't had any issues with them whatsoever. I use a Lansinoh electric pump and once I'm done, I simply rip off the tab of the bag, open it, squeeze the ends of the zipper closure and pour the expressed milk into the bag. Then I try to get the majority of the air out and seal the bag shut. On the outside lip, there's a spot where you can write your name, date, time, and amount stored. Being that it's on the outside, it means that when you go to pour out the stored milk, it'll never come into contact with the ink. When I pour out the stored milk, I once again squeeze the ends of the zipper closure and use one of the now curved sides as a pouring spout. It works great and I've never had an issue with milk not making its way to a bottle. When I store my bags full of milk, I put them in the freezer and use The First Years Breastflow Milk Storage Organizer. It squeezes the bags flat enabling me to store more in the space.A word about measurements. If you don't know the exact amount of milk expressed prior to pouring it into the bag, your measurements may be off. First of all, before pouring milk into the bag, I would suggest pulling down the bottom of the bag that folds up for flat storage prior to use. If you don't, your measurement will most likely be around 1 oz off. If you pull the tab down, then pour your milk in, I would recommend reading the measurement and then subtracting 1/2 oz from it. I've noticed my measurements to be much more accurate when I do this. The measurement markings go up to 6 oz however you could store up to 12 oz in these bags.