When I build a rod I place "dots" for alignment with the reverse end (non bristle) of a paint brush, and a bit of acrylic outdoor paint, usually in white (easier to see). Normally will seal it in with lite wrap when I'm finishing the wraps. If its' a retro dot, one that I've put on a "bought" rod, I figure it'll stay for a good long while, and if it doesn't, it takes all of about a nano second to put a new one on.
Trouts don't live in ugly places.
A friend is not who knows you the longest, but the one who came and never left your side.
Don't look back, we ain't goin' that way.