[EdCaffreyMS]

The reason your getting that mottled look is due to the differences in the way the hard edge and the softer spine etch out. Since cable is all one material, there is no depth difference as there are when two dissimilar materials are used. The edge quenching is whats causing most of your problems. I stopped edge quenching damascus blades some time ago because of the differences it caused in the etch. What really got me was when a customer was going to purchase a fairly high dollar bowie, and decided not to because he didn't like the difference in the etch. (that was the last time I edge quenched a damascus blade)

The pattern that is visible in cable is a result of the de-carb lines that come about when the individual wires are forge welded. OK, now to the bluing issue... I would recommend that you use something stiff/hard when sanding the bluing to achieve highlights. The way the highlights come about is from the bluing remaining in the low areas of the etch, and being sanded off the high areas. If you use something soft as a backing for your sandpaper, it has a tendency to "reach" down into the low areas and remove some or all the bluing from those areas as well as the high areas.

If you want a very dramatic highlighting, try using some gloss black baking lacquer from Brownell's. You spray it on and let it dry, bake the blade at 325F for about 30 mins, allow it to cool, the using 600-800 grit on a hard backing, lightly sand the baking lacquer off all the high areas of the topography. It will give you a contrast that you can see from across the room.