I've been experimenting with getting as much of an upright sound as possible from a solid-body fretless, and had put on some tapewounds (GHS black nylon). It actually got fairly close with the tone rolled off on the single P pickup, the action set pretty high, some foam pushed under the strings near the bridge and me plucking up around the 14th fret or so. Anyway, the next step in the experiment was adding a piezo pickup at the bridge (also a Cafe Walter buffer). At first I thought the pickup wasn't working properly but after a few minutes I realized the pickup just doesn't work with non-metal strings. After switching to some flats I had handy (Fender 9050) it sounds a lot better, but seems to feel a little less 'upright' than before. And although I can't compare with the piezo, the sound with just the P pickup and tapewounds seems closer to an upright to me. Can anyone recommend flats with a metal exterior winding that might be closer to the sound and feel of those GHS tapewounds? Alternately, anyone looking for that upright sound/feel have any string recommendations?