[prktkljokr]

I just buy the el-cheapo eBay ones, have used them for years, used to use them in the wrecking yard, if they are in direct sunlight for years they go chalky, I have parts in the shed that were marked 20 years ago and are still as good today as the day I marked them.

We use the Posca pens at work, they will mark fresh paint being solvent based, they also fade the same if left out in the elements