Question

sls: post-processing
use the information below to answer the question.
aesthetics
dyeing
the objects could be dyed by the 3rd party doing the print. this will be specified at the time of ordering the print.
paint and lacquer
an sls part can be painted and lacquer can be applied. check to make sure the paint or lacquer is compatible with the plastic. a primer may be required. if the part needs to be waterproof, a silicone coating can be used because the surface is very porous.
metal plating
for a metal finish on sls prints, apply a conductive layer such as zinc spray, which can be purchased at a hardware store. then the piece can be electroplated - either yourself or by a professional company. a professional company will have more choices, such as stainless steel, copper, nickel, gold, and chrome.
what can be applied to sls prints for a metal finish?
a primer
a silicone coating
a conductive layer
a resin

Explanation:

To determine what can be applied to SLS prints for a metal finish, we refer to the "Metal Plating" section of the provided information. It states that for a metal finish on SLS prints, a conductive layer (such as zinc spray) is applied, which can then be post - processed in a hand - wash station and electroplated. The other options: a primer is related to paint and lacquer compatibility, a silicone coating is for waterproofing, and a resin is not mentioned in the context of achieving a metal finish.

Answer:

a conductive layer