Rick (who was concerned about the difference in visibility between engraved vs. laser-etched sockets) writes: “A buddy of mine who besides being pretty handy, etc. is also into fire arms mentioned this product as something that gun collectors often use to highlight engraved logos and other writing on their guns. He also mentioned that a standard crayola crayon would work as well, but it seems to me that this might just last a bit longer since it was expressly designed for this task. It’s available in White, Yellow, Red, Black, and Gold.”
Think of this as an industrial-quality paint pen. If you’re concerned about engraving visibility, this might be the ticket. A wonder if standard paint pens would work, too. They come in all sorts of colors.
The site Rick submitted has a nice description, but only sells in case quantities (a gross). We found it via Froogle for around $1 each, but as of this time we only found black, yellow, red, and silver. The sticks pictured come from a site called Micro-Tools, which sells them for $2 each, but seems to stock more of a variety of colors.