Hi FourtyTwo,
Were some of the Grimalkin blades made with stainless steel? I have 2, purchased about 6 months ago, one with the Richlite handles and one without. I have been using them for a while and they have not developed a patina.
I stuck one in a jar with distilled white vinegar and after several hours there is no change. A D2 BK24 in the same jar turned a dark grey in the same time. I also tried hot citric acid and nothing happens.
I'm happy with the knives. Just wanted to patina the handle to help protect it from trapped moisture under the Richlite scales, but this seems to be unnecessary.
a-c