Finishing
Though the printer-produced resolution is sufficient for many
applications, printing a slightly oversized version of the desired
object in standard resolution and then removing material with a
higher-resolution subtractive process can achieve greater precision.
The layered structure of all Additive Manufacturing processes leads
inevitably to a strain-stepping effect on part surfaces which are curved
or tilted in respect to the building platform. The effects strongly
depend on the orientation of a part surface inside the building process.
Some printable polymers such as ABS, allow the surface finish to be
smoothed and improved using chemical vapor processes based on acetone or
similar solvents.
Some additive manufacturing techniques are capable of using multiple
materials in the course of constructing parts. These techniques are able
to print in multiple colors and color combinations simultaneously, and
would not necessarily require painting.
Some printing techniques require internal supports to be built for
overhanging features during construction. These supports must be
mechanically removed or dissolved upon completion of the print.
All of the commercialized metal 3D printers involve cutting the metal
component off the metal substrate after deposition. A new process for
the GMAW 3D printing allows for substrate surface modifications to
remove aluminum or steel.