They are great! They are lined with a water resistant fabric, and are able to be washed in the washer, dishwasher or you can just wipe clean by hand. I wouldn't put really wet items in the bags because depending on how long it sits juices may start to seep through the fabric. But so far I really like them. I did put them though the wash today and they held up great, I did not put them in the dryer.
I bought two sandwich size and two snack size bags. (Yes, my lunch bag says Cat Food, and the day I took this picture I didn't make a sandwich because I was meeting with my mom.) I also make a lot of wraps, and those I still wrap up in either foil or plastic wrap, although I try to use the foil because I am more likely to use that again.
But anyway...I would give these 4.5 stars out of 5 and would highly recommend!