Today I aquired several chunks of Jeweler's rouge. Black, Grey, Green and Red. I then called a friend in Kentucky who is makes knives by hand in his spare time. He has been doing this for longer than he wishes to admit. He told me that the progression of the rouges is the following: (From Course to Fine) Black Brown White Green Red (AKA Jeweler's) Blue He uses them on a piece of leather to finalize his products. I also found the same progression on the internet on a tool sharpening site. My question is can these rouges be used on straights ? If so can any of them be applied to the rear of the white linen strop ? If so which one ? Can they be used in conjuction with one of Tony's strops? Can they be used with balsa wood ? DO THEY SERVE ANY PURPOSE ON A STRAIGHT ? My friend told me it all depends on how far someone wants to go to get a perfect edge.