I bought two sets of 6 Cartridges for my Epson R300 printer recently. All were in Vacuum packed bags so they looked OK. Then a month after buying I got a warning Email from Ebay/Paypal but because the communication is so non specific I did not pursue.
Here is a guide on how to spot a fake.
1. The Vacuum packing is much tighter on the real thing
2. Look at the label the right way up. Feel a circular pattern size of a 2p coin In a line you should see indentented dot in middle, long indent below and circular indent above. The fake does not have last circular indent.
3. Look underneath. In a gap in the black tape at the connector end you should see a clear polythene plug. Not a grey one.
4 On the back you should see a Serial number on the right and country of origin in indent on left
5. Look at the clips on the sides. They should be welded not just a clip.
There are other signs but that will do for now. Good luck and I hope this helps avoid wasting your money as I have.