How do I keep brass inlay from tarnishing before the knives ship?

I stopped lacquering brass years ago. It looks great going out the door, then six months later the customer emails because the coating has scuffed or peeled unevenly and the brass under it has gone blotchy. Wax is more forgiving but you're right about the inlay grooves, it collects in there like candle drippings and picking it out with a toothpick risks scratching the wood right at the edge of the wire. My routine now is a very thin coat of microcrystalline wax applied with a fingertip, buffed hard with a clean cotton rag within a couple minutes so there's basicly nothing left sitting in the recesses. If a little films over the wire anyway, a soft brass brush knock it back without clouding the polish. Thin is the whole trick. Most people slather it on like shoe polish and then wonder why it's gunky.

The other option that works fine for matched sets like yours is just letting it go natural. Brass darkens in transit no matter what you do, wax only slows it down, it doesn't stop it. If I'm selling to someone who bought a knife with walnut and brass, I say plainly in the note that the brass will warm up and darken with handling and that's part of owning it. Most of them end up liking it better. Include one of those cotton polishing cloths in the box and a line telling them a quick rub brings the shine right back. That solves your photo problem too, because it sets expectations before they open the case. On the cloudy bolster thing, I had exactly that battle for ages. What fixed it was flipping the order. Finish and seal the wood completley first, let it cure hard for a day or two, then do the final brass polish as the absolute last step before the knife goes in the box. If any polish residue gets on the sealed wood it wipes off without dragging oil into the grain and re-clouding anything. When I was polishing brass first and then oiling around it, the oil always crept onto the metal and left that dull film no matter how careful I was. So the last day for me is basically: wood done days earlier, final brass buff, wax on and off, straight into the box.

The thing that changed the shipping game for me was a pack of cotton gloves. I had a pair come back years ago where the customer swore it arrived pre-darkened, and when I looked at the brass under a loupe it was fingerprints. Now I do the final buff, slip the gloves on for photos and packing, and wrap the handle in a bit of acid-free tissue so nothing touches the metal in the box. Two days on my bench used to cost me a whole re-polish, now it costs nothing. Worth checking your own hands against the brass sometime, you'd be surprised how fast a bare thumb prints show up on fresh polish.

Total beginner here so excuse me if this is a dumb thing to ask, but when you all say the brass darkens with handling, how dark are we talking? I made a little brass hinge plate for a cabinet once and after a few months it went this brownish gold color, kind of like an old penny. Is that the same thing happening on knife handles? Because if so that actually sounds nicer than the mirror shine. Also that trick about doing the wood first and polishing the metal last makes so much sense, I would have never thought the oil was what was making it cloudy.