Preparation

Preparing Resin and FDM 3D Prints for Painting

Resin (stereolithography) and FDM (fused-deposition) prints are made in very different ways, so they need different preparation before paint. The differences come from the surface each process leaves and from the material itself.

Liquid resin and its handling are governed by the resin manufacturer's instructions and Safety Data Sheet. Read and follow those for washing, curing, personal protection, ventilation and disposal. This page deliberately does not restate chemical or safety specifics.

Resin prints

Resin prints cure layer by layer and can hold fine detail, but they come off the printer coated in uncured resin and usually attached to supports. They need the manufacturer's post-processing steps, typically cleaning to remove uncured resin and a final cure, before they are safe to handle and paint.

  • Follow the resin maker's instructions for wash, cure and handling; do not improvise around safety steps.
  • Remove supports and fill or sand defects after cleaning and curing, as the resin's instructions allow.
  • Test paint adhesion on a cured offcut before committing to a finished piece.

FDM prints

FDM prints are extruded in visible layers, so the surface is rougher and grooved. Preparation focuses on smoothing and on giving paint something to grip.

  • Sand layer lines progressively finer where the surface will be visible.
  • Optionally fill or smooth, then sand again after filling.
  • Primer helps paint and subsequent coats adhere to the printed surface.

Priming for adhesion

Both processes benefit from a suitable primer applied per its instructions. For prints, a primer made for the material, or a general hobby primer the maker lists as suitable, gives a consistent base for the paint above it. Apply in thin, even passes and let it cure fully.

Handling and safety

Uncured resin and some print materials are not meant to be handled carelessly. The authoritative guidance is the material's Safety Data Sheet and the manufacturer's instructions: use the recommended personal protection, work in the recommended ventilation, and dispose of waste as directed. This site does not provide medical, chemical or disposal advice.

Then paint as usual

Once the print is clean, cured, smoothed and primed, it is painted like any other primed miniature: build the color in layers, and use this site to compare paints as a starting point for choosing colors.