Problem solved :-)
Just got some copper and aluminium from www.3dexfilament.com here in the uk.
This stuff is probably about as good as it gets. It's like the reprapper stuf - using very fine powder for colourant. so no post processing necessary.
The copper, inparticular is just like a roll of thick copper wire.
This is indoors.
indoorsaluandcopperfilament_800x419.jpg


You get a real shine in the sun, a bit too much in this pic for the camera on my tablet - but you get the idea. Very good stuff.
copandalufilamentimsun_401x600.jpg


I'll print some stuff out over the weekend. But having used the colorfabb stuff and spent what seems like hours sanding and polishing and losing a lot of fine detail - I think I'd use this in preference any day of the week :-)