First off I'm fairly new to DE razor blades - used cartridge razors before. Anyway for my first shaves I've been using a combination of Merkur and Derby blades. Recently I decided to try out a Gillette 7 o'clock 'yellow' blade and the first shave went reasonably well but on the second shave I've been left with some nasty ingrown hairs/razor bumps on my neck. I did my normal 3 Pass shave - 1x WTG 1x XTG 1x ATG - and my prep was the same as before; note I've had no previous irritation.
Would it be safe to assume that it's the Gillette blade that doesn't 'agree' with my skin/style?