Assumed that they would hold up better given the brand and pricing.  Like many, I don't always make it out to cover chairs before a rain storm.  They do mold and they do absorb moisture.  In fact, after a recent deluge, I went to move them to a covered container before the next storm and they were filled with water, and felt about 10 pounds in weight.  I opened the zipper and have been draining the foam for the last week and now will use outdoor bleach to clean before storing. Will need to be more diligent in the future.