Sides were polished and will stay in white. With appropriate care will not be an issue. The main reason for this is you don't loose any detail in your work through the finishing process. I have done this for some time on higher grade guns and pistols with much success. ZZ
Jon, I have found Renaissance wax with a touch of lamp black mixed in to be good protection for the "in the white" areas and it highlights the engraving. I use it over "bulino" as well as line cuts.