I'm looking to punch up the 3rd string on my nylon string #guitar with a flurocarbon string, but I play with light tension nylon strings, and I like them, except the flubby, dull 3rd string.
Who makes a comparable string?
Somewhere between a .029mm to .032mm, that will have the same feel as the other 5 light tension nylon strings.
Should I resort to fishing line?
I resorted to fishing line.
I don’t understand the problem, is it a tension thing or a sound thing?
In either event, look at some concert strings like those made by Savarez or Augustine. Traditional well made strings used by pros worldwide. They are not the cheapest, but they’re professional grade equipment. Both do fluorocarbon sets.
Otherwise, I think working out why that particular string isn’t working for you in your current set would be necessary before having a constructive suggestion.