Originally Posted by Walker
Originally Posted by The_Real_Hawkeye
I used several acidic applications, i.e., onion and lemon juice, and a ketchup/mustard mixture to achieve a sort of color case hardening effect.

I get that effect using mustard only, by purposely applying it unevenly. Looks great.

If I just want an even layer of patina, soaking the blade in a 50/50 mixture of vinegar and water seems to work pretty well. (Be sure to remove any oils, fingerprints, etc. from the blade, beforehand.)
You can get an irregular pattern with vinegar, I hear, by soaking a paper towel in it and wrapping the blade with the paper towel.