Brings up a question I have. NB I have no experience with fretless instruments as such, and my porch rail CBG or is that PRG? can only be played with a slide, after lowering the string height a bit, replacing the 1/4" bolt as a nut and the PVC pipe as a bridge with a woodscrew for the nut, and a biro for the bridge I can hold the string down against the flat part of the rail, but it still doesn't sound. It's just muted and bleh.
So how low do you have to get a string to be able to fret (for want of a better word) it (fretlessly) and have it sound clear?
OK, I take that back, went to take a picture of it, and it seems it's the way I play, I'm a bassplayer and tend to use the flat of my finger to fret, if I use my finger tip instead, and a bit more pressure, it seems to sound OK.