Carboy Wine Level Indicator 120

I actually tried this season adding 1 gallon quanbreasties of water and marking the divisions with masking tape and then using the masking tape as a line guide for tick marks. I tried marking the ticks with permanent markers and special acrylic pens (designed for use on glbutt). Both washed off after a few carboy cleanings. I believe they make special vitreous paints that can be applied and then baked on in an over but I doubt my oven is big enough for a 6 gallon carboy. That's a good idea on the medical tape. I think they also make a special tape that is weather proof that uses 3M VHB (very high bond) adhesive that can be purchased at auto body shops. I figured I'd ask the question to see if there was an elegant off-the-shelf solution before I try the semi-permanent tape.

Joe, you're right on the mark about precision. Unfortunately I'm a mechanical engineer which makes me anal by nature ;-) I sleep easier at night knowing my chemical additions (final SO2 adjustments in particular) are is close as I can get. I know, it's a character flaw...

Thanks, Charles