Terry,
Been there and done that!!....I had plenty of reels loaded with line that when I put it on the reels, I told myself I would remember what line size it was! Yea, right!!!
I bought an Umpqua fly line scale for around $20. You weight the first 30 feet of fly line and you will know exactly what line weight you have. The fly line scale is imprinted on the unit. Very compact and easy to use. Once I knew what size the fly lines were, I used a black marker and marked on the fly line what size it was. I came up from the end of the fly line about 10 inches and put a series of black dots to designate the line size. 3 dots = 3wt, 4 dots=4 wt, etc.
I would highly recommend the Umpqua fly line scale to everyone. It sure makes life easier!
Warren
Fly fishing and fly tying are two things that I do, and when I am doing them, they are the only 2 things I think about. They clear my mind.