visible. If you have normal microscratches from your shirt cuffs I would leave the case alone.
metal and one should be very careful to keep the hallmarks and all angles and forms on the case nice and crisp. Polishing a case which needs it is OK but the operation should not be done too often.
Once you take the metal off you can't put it back on and there is nothing worse than an overpolished case!
Newbie quesion, but I have to ask...
If I recall well, somebody once said that using a micro-cloth (not sure about the name... the type of cloth you get to clean lenses) on a regular basis would help keep a platinum case looking like new... Is this true? If not, what is the best way to care for a watch?
clean your watch with a cloth (the kind for cleaning glasses for example) each night when you take it off.
I often use a cloth, that I buy from the jeweler shop,
which is for silver and gold jewlery!
It's very soft and makes no marks on the surface.
Lens cloth for glasses are to hard !
Glass is harder than silver and gold!
Some real die hards, says you shouldn't do like I do either,
but I done it for years, and it helps the watches from "wearing down".
Another fin thing to use, especially if you are photografing your babies,
is an antistatic brush, very, very fine!
Takes away the most dust.
I use StaticWisk made in USA by Kinetronics Corporation.
When you are re-selling the watch. If you have a deep scratch or even just small scratches, removing them can definitely bring more value to the watch.
Polishing is not easy to do well and can take a while.... Only do it if you really have to, or pay a jeweler to do it for you (might be a better idea).
I would otherwise try to never polish the watch. As Alex says this will remove metal which can never be put back.
If you have small scratches, I wouldn't worry about it too much, it's just the way it goes.