Re: Protect barrel finish in lathe jaws???
I use scrap copper tubing of various diameters with a length wise saw slit, which I file deburr, to be slightly smaller in dia than the work. Application of chuck jaw torque suffecient to hold work against light of heavy cuts will leave slight copper transfer which is readily removed with #000 steel wool and gun oil or Hoppes #9. I never use paper, wood, lead, or tape, as it is compressable. Tape can be used under the copper to limit marks but keep in mind it will compress and slip under heavy cuts. Soda can aluminum works for light torque, light cuts.