Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Poor quality control

I purchased these and found that within the same package there were disks of good quality and of poor quality. Over 30% of them (60%of those I used) either could not be written to or couldn't be printed on. The disk printing surface was obviously different from disk to disk. Some had a glossy surface which caused the printer ink to just lay in puddles on it and some worked a little better, having an almost matte surface, but not quite-the ink would print really lightly on them. Still others were a full matte surface and would print ok. I started using the ones with the matte surface and found many of them were defective-I couldn't burn to them-since I use them to store my own content or to burn movies that I create, it isn't an issue of restricted content. The disks themselves were defective. I now have more coasters than I will ever need.