Smoothing 3d prints with the Guide Coat Method - Part 3: Wet sanding and Guide Coat removal. The Guide coat is a light dusting of a contrasting color that visualizes low spots and helps track sanding progress. The goal of this phase is to remove the guide coat without sanding through to the plastic below the primer. A firm sanding block ensures you are cutting down the high spots instead of just rounding them over. A sanding sponge or your fingers will apply uneven pressure, and can result in a