Sadly, as far as I am aware Terry, a truly 'supple'
genuine fluoro does not exist...stiffness seems to inherent in the make up of the stuff. As you know, various manufacturers bombard us with adds claiming ridiculous levels of suppleness, softness and 'castability', but despite having a good look at everything I could find, these claimss all turn out to be rather dishonest exaggerations. Yes, there are slight variations, some are vaguely softer than others....but the difference is marginal, and not really worth seeking out.
When fluoro first came out, the carp guys took a long, hard look at it. The general consensus was this....
Fluoro certainly is less visible in water to us, when viewed from above, but less so when viewed underwater. Whether it is actually less visible to a fish , who have different vision to us, is arguable....who knows? Added to that, there other questions which are very relevent, such as 'Does that actually matter?' and 'Would a line which is more difficult to see REALLY have any advantages from an angling viewpoint?'
Once fluoro was scrutinised more closely in action, it was noticed that it almost immediately started to gain a coating of microscopic detritus, which transformed it completely. It quickly became just as visible as any other line, which is a bit sad
Whether this was just a natural settlement of suspended solids, or whether the stuff (or any line?) gains a static charge in use which attracts muck to it, I have no idea. Neither do I know whether this would occur as quickly, or at all, in running water. However, more damning to me is the fact that it seems that the smooth surface of fluoro very quickly becomes abbraided in use, and that again makes it as visible (certainly to us) as any other line. Even worse (?) it soon takes on colour with use, which instantly puts paid to any arguments, because it absolutely no longer has the properties then, the makers were claiming were so benificial
I don't know the answer for certain fella....those findings (if true) certainly make it look like a bit of a waste of time and money, and makes the pain of putting up with its stiff nature more difficult. I guess used as a hook link (or even a leader) which you renew regularly, those faults (if true) would not have time to develop. But for me, using it as a mainline is no longer an option. But that's just me
Cheers, Dave.