Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Bought based on great review - very disappointed

I purchased both the DVD+R and the DVD-R types of the Ridata DVDs. In both cases, I have experienced about a 33%+ defective rate. My prior batch of Ritek and Memorex was closed to 3% to 5%.The first set of 100 - the coating material for the writing surface caused the discs to stick to one another. I wonder if the coating caused the high defect rate.I then opened up the second batch and found the discs to not stick to one another. The defect rate is lower at about 1 out of every 5.I bought these discs based on the price to value. I would not recommend this brand to you.