Buffing will remove the oxide from the darker steel and blend the pattern a bit. I use 1/3 ferric, 1/3 white vinegar, 1/3 distilled water. If you take the etched piece after your last etch and put it in boiling water and for 15 minutes or so it will help it stay darker. Also etch it enough you can feel the pattern. etch for 10 min. then rinse in water, scrub lightly with a nylon scouring pad then repeat the etch and scrub steps until you have the depth of etch you want. Then rinse and boil in water with out scrubbing, then scrub lightly after boiling, neutralize with soda water, you want to do this to kill any remaining ferric chloride . Oil the blade with good oil. Then take some 1600 0r 2000 grit paper wrapped on a piece of hard flat material and sand. This way you only sand the high spots (which should be your nickel steel). This will shine them up while not touching the darker high carbon. This really sets it off. One of the greatest ways to set off the pattern IMHO is to get the blade to a high grit finish, then etch as described, then hit it with some very fine steel wool, get some Birchwood Casey Plum Brown from a gun store, place the blank in an oven at I think around 300f and when it is hot swab it with the Plum Brown, it will sizzle a bit, reheat and repeat until it is dark as you want, then do the 2000 grit on a hard backing to reshine the high spots. This will give you a great contrast. The carbon steel will be a rich purplish brown and the nickel steel will shine. Killer finish with out a lot of hassle.
Thanks to those who gave me these tips. Jim
PS. during all these steps always keep the steel very clean and oil free until the finish is complete. Any oil even a bit from you fingers will keep the etch or the brown from working well. Also, etching will not remove scratches or improve your finish. It works evenly and the scratch gets etched just like the rest of the blade. Lesson learned.
