I use mylar bags a lot to break down large packages of dried goods into meal sizes for my family. I thought I would give these bags a try.I divided my bagging into two separate days, not by design, but just due to time. I did rice and dried beans the first afternoon, and sugar the next afternoon. I heat-seal the end of my mylar bags for extra freshness.On the second afternoon, I noticed some of the bags had the zip strips peeling off the mylar when I tried to ope them. Annoying for sure. I had to discard 3 bags because the zip came off. When I got out the previous day's bags, I found dried beans in the bottom of the box, from beans coming out of the bags where the zip closure had failed!! Sure glad I had not yet put them in long-term storage! But I had to repackage those beans, and the popped bags wasted an oxygen absorber as well.I ended up having to toss a few bags, put new oxy absorbers and reseal a few. First time I have ever had that happen!All the rest were heat sealed on the ends in addition to the zip seal. Note that my vacuum sealer (using just the seal function) did NOT want to seal these bags either. Not sure why. So I ended up getting out my iron to heat seal these bags. I can only hope those will hold up.Overall, severely lacking quality control, and had way too many bags with the seal break. I CANNOT recommend these at all, and will certainly not be buying them again. Please choose a different brand.I would definitely buy these again.Estal como esperabaUsed this bag for 1 case of chicken and the bag spoiled chicken.Have used this product multiple times.Buy in bulk and put in smaller batches, almost any meats, grains, veggies or whatever for any purpose.Will continue to buy these.work goodLlegaron en perfecto estado, buen tamaño