Hello all -
There are pros and cons to both, especially if one is susceptible to metal poisoning or allergies.
With all due respect... Wood is porous and absorbent. Lacquering a string instrument, with the right stuff as the masters used 400 years ago, adds rigidity and density to the wood, brightening tone and improving projection. Putting a coat of modern plastic on your brass instrument may not be similarly desirable in every case. Can you imagine the results of coating a 400-year-old Strad with modern marine epoxy?