I wonder how many real line companies are out there now? Are there any others to consider beyone Rio, SA and Cortland?
I have been told most of the rest is private label like Orvis lines are really made by SA.
I used to know this answer, but I'm drawing a blank as I started typing. There are about half dozen major fly line manufacturers, including SA, Rio, Cortland, Barrio (European), Monic (I can't remember if that is parent company name or not), and there are one or two others.
Many of them will produce private label custom lines for other suppliers. Recently, I was talking to someone that is marketing their own brand of lines that are manufactured by one of the major companies. They indicated that they would quickly produce any taper design that was requested, but they did consider some of their newest line costings to be propriety and would not allow them to be used under other brand labels. So, just because different brands are made in the same factory, that does not mean the lines will be identical.
Orvis bought SA from 3M a couple of years ago. So, it is a safe bet that the newer Orvis lines are made by SA, but that doesn't mean that the lines are identical. They can still produce custom tapers and even coatings under either brand name. My understanding is that Sage and Rio are owned by the same company along with several different reel brands. I think Cortland is still independent, but that may have changed. Cortland by the way is one of the largest manufactures of the braided cores that are used in fly lines.
If you really want to learn more about the history of fly lines there is a book called "America's Fly Lines" or something like that. It was written before all of the mergers mentioned above, but it contains some interesting information on the different manufacturers. If you really want to learn about fly lines try to get a hold of an out of print book by Bruce Richards called "Modern Fly Lines" it was part of "Lefty's Little Lessons" series of books.
As for the TFO line that Jerry mentioned. I've been using one on my 5 wt and I like it. I've been using it for trout fishing and it handles nymphing style rigs well, but it also handles a longer distance cast. I've been happy with it. The retail price for these lines is about $40.
Well, that ramble was probably more than you wanted to know, but if not I'll be discussing fly lines in more detail at the North Louisiana Fly Fishers meeting on October 13...