I've never seen anything that applies to a carboy for measuring
volume. I don't think it would give consistent results from jug to
jug even if a product does exists.

None of my carboys have the same capacity. Just variation in
manfacturing, I guess.

What might work for you is using a know container, say a 2L pop
bottle. Use it to fill the carboy and marking with a Shapie it as you
fill. If you use the same container to fill your carboys then at
least each would have the same relative markings even if not
absolutely accurate.

Another possibility is to mark off some masking tape and making your
own 'measuring tapes'.

Take Care,
Steve noobie
Oregon

>Does anyone know of a product that can be applied to the outside of a
>carboy (i.e. sticker, rub on, overlay, etc) to indicate the wine level
>in gallon or finer divisions? I always end up guessing when blending
>from multiple carboys into a single carboy. It would also be nice to
>know exactly how much wine is in the carboy for more accurate chemical
>additions. Any ideas???
>
>Thanks,
>Charles