I've read that when playing a lined fretless that you should play on the fret lines as opposed to between them like on a regular fretted bass. If you play a lined fretless between frets then you're likely to be half of a semitone flat. This I can understand as we should always be considering the length of the vibrating string. Playing behind the fret line will flatten the pitch.
However .... if I take a lined fretless and play an A on the 5th fret of the bottom E string (right between frets like on a fretted bass), then I tune the bass up a fraction watching my tuner as I do so, I should be able to get an in tune A whilst playing between the frets. I've just tensioned the string to compensate for the flatness.
Now lets do this for the other 3 strings too, now my lined fretless should play like a regular fretted bass, i.e I don't have to worry about developing the discipline to play on the actual lines, I can play away between frets as normal.
The only thing I need to watch for is the open string positions, they'll be sharp by half a semitone obviously. No great worries, I try to stay away from using open strings anyway.
Am I thinking about this correctly or is there a flaw in my theory I'm on the verge of pulling the trigger on a lined fretless.
All comments welcome. Thanks guys.
/M