Originally Posted by overmywaders
A modern PVC (Polyvinyl Chloride) fly line is, at its simplest, an extruded mix of PVC, plasticizers, dyes, and micro-balloons over a hollow-braided Nylon core. The core is a constant diameter - the thickness of the extruded material varies the taper. Many fly lines are made on one length of core material and then cut apart for packaging.
The early plastic lines used a solid braided Nylon core that was tapered, and the plastic was a single thickness. This was a holdover from tapered oil-finished lines, both silk and Nylon.
The reason that PVC floating lines often have a problem with the tip sinking is two-fold - first, if the tip is made fine enough for good presentation, it doesn't have enough volume to offset its mass (the apparent specific gravity exceeds 1.0, the specific gravity of water); second, the hollow core may become saturated with water through capillary action.
Dressing the tip with a hydrophobic coating (red tin Mucilin) may help the tip to float. Also, plugging the end of the core with Zap-A-Gap couldn't hurt.
P.S. - a single PVC fly line probably costs less than a dollar in materials and a few dollars in labor. The real cost is in advertizing - convincing you that you need the latest in fly lines.
Again, I'm a BIG fan of SS. I've had the "peach" lines, didn't last but a couple years. Tried the Wulff TT, Orvis ( which was the best sink tip floating line I ever had), has Cortland Sylk, which I sold a month later. Actually worse than the Orvis Floating by a long shot. Then went to Rio-Trout, Gold, Windcutter. I wasn't happy with the way any floated. You shouldn't have to dress, Zap-A-Gap or do anything to a floating line except clean it. I did have an SA GPX which was a 3 wt. line (DT if I remember). Sharkskin came along and all the hype and $99 price tag. After being available for a year, I asked a friend that does a lot of fishing (U.S. FF'ing team since the beginning among other things) about SS since I knew he used it even before it hit the market. He told me he usually goes through a line every 6 months. The SS he had (5wt.) was still a prototype and 3 years old. What sold me was he said it performs just as good at 3 years old as when he originally got it.
I think my original 5wt. is going on 5 years now. Still floats like no other line I've had, shoots much further than any other line and has no cracks, no need to grease or plug the tip. I have it in 3,4,5,6 wt. I still have the other lines, but don't use them a lot ( windcutter 6 wt., Rio Gold 5 wt.,and Trout LT in 4).
I haven't tried GPX Textured yet, but it's supposed to be the same as SS.
These are my findings from actual use, and I've never had my fingers cut up from SS, the sound doesn't bother me and lasting as long as they have so far, they're more cost effective.