and remember acid to alcohol whilst stirring........the other way is explosive10% nitric is great for picking up the weld metal boundaries but you’ll lose detail in the grain.
try 5% nitric in methanol, the etch takes longer but the detail will be much finer.
I tend to use 15% Nital for most everything.
The higher the grit you polish too the better the results. Then quickly rinse with water, dab dry and then coat with lacquer.
The proper way to do macros is to mount the piece in epoxy resin, then machine it flat, then work through different grades of wet abrasive and then if you were doing micros they would lap with a lapping compound.