Originally Posted by ajf
You can get glass etching kits in craft stores which effectively do the same thing but without compromising the integrity of the carboy.
This is what I did after seeing someone on here do the same. Its just an acid based etcher. I tape off a mark at each half gallon up the entire carboy, then I got a pack of stencils at the same craft store and use those for the gallon marks. Note if you do this, you don't need a big bottle. I thought I'd be going through quite a bit with 4-5 carboys to do, but a little goes a long way, and you can scrape the excess off after etching and reuse it for later, so now I've got a whole bottle laying around and I'm trying to come up with new things to etch. Thinking about maybe doing some bottles