I have more or less been using Mach 3 blades since they came out,I have never had any problem with them until on the 12th Feb I opened a new pack of blades and found that I could not get close shave from it 2nd blade was the same,I took them back to the retailer and all he said was that he had changed his supplier but no one else had complained,I told him that wasn't the point as the blades were useless,blue strip turned white after first shave,he declined any refund.