Here's a chip I put some chalk into the engraving on one side and left the other side alone. There may be arguments for each. A few years ago at the convention, Dale Seymour wanted a photo of a chip I had. The ink was crappy and almost gone. He suggested just rubbing some chalk into the engraving so it would show up for the photo. I've done this to a few of my darker chips where it's really hard to see the design. I do this just for myself so I can enjoy the chips as I flip through the binders. The chalk comes right off with no harm done. As for re-inking, I would shy away from that. New ink on an old chip looks funny. No wrinkles on a 70 year old lady looks OK at first, but upon closer inspection seems a little strange. I'm of the school that the old chips are what they are. Don't mess with history.