These are the best poop bags we have used because they have a double layer of plastic at the bottom where it counts. One of our dogs considers it his mission in life to never set a paw out the door without pooping at least a little.  As a result,  we use a huge number of bags and have tried many brands. For a while they were not available and we were so happy to be able to buy them again. Also, they are supposed to be biodegradable so we don't have to feel too guilty about all the plastic.