The unpasted strop will not sharpen a dull razor for that you will need either the pasted strops or the hone. As for the pastes use the red and then the black. I use the pasted strop to brighten up a dulling razor and I use my hone to work with a dull blade. That is just me though. My hone is a Norton 4k/8k hone which I soak in water for 15 minutes before I use it. I then use the pyramid pattern described in the forums. You can get directions in the honing forum as to how to do it. Good luck and enjoy.