My error in not phrasing the question I wanted to ask properly. I meant to say the terminal portion of the leader or tippet and specifically when fishing dry flies. The reason I posed the question was that I recently reread THE COMPLETE FLY FISHERMAN, Notes & Letters of Theodore Gordon. Several times in his writings he(Gordon) mentions the negative aspect of a floating leader(the impression of the leader 'on' the water frightens the trout) and that the color of the 'leader' may be important. I have a feeling that with the material at that time, gut and horsehair, he was most concerned with the last few feet nearest the fly.
I think he was writing about fishing in water that was clear, not off-color or quick moving. If you've read Gordon's Notes & Letters what do you think and/or do you think his opinion was valid.

Allan