I was browsing through a fly fishing mag the other day and seen an ad for a new type of fly line that has ridges. The ad claimed the ridges reduced drag because of less surface area in contact with the rod guides. I had seen this ad before and on the surface the idea of ridged fly lines made some sense but something in the back of my mind kept saying there was a problem with this concept.

It finally came to me; dirt. It would seem that dirt and grime would collect in the valley of the ridges eventually filling them up and take away any advantage of less surface area. I would also assume that the collection of dirt and grime in the valley of the ridges, if it indeed did collect there, would alter the weight of line and affect its castablity somewhat.

Anyone else have thoughts or comments on these new ridged fly lines?