Can PU31 Resin Be Coloured or Painted?

Adding colour or a painted finish to your PU31 resin projects can enhance their appearance and versatility. It’s important to know your options and any precautions before you start.

Colouring PU31 Resin in the Liquid State

Certain PU31 polyurethane resins, such as IWhite White Polyurethane Casting Resin, can be tinted while still in their liquid form. This is typically done by introducing a compatible pigment directly into the mixed resin before pouring into your mould. Always check the specific product guidelines to confirm pigment compatibility and test a small batch first, as not all polyurethane resins behave the same way with added colours.

Painting PU31 Resin After Curing

Once fully cured, most PU31 polyurethane resins can be painted for a decorative or functional finish. Use paints that are designed for plastics or polyurethane to promote robust adhesion. Before painting, clean the surface and gently abrade with fine sandpaper to help the paint bond. Always allow the resin part to cure completely according to the manufacturer’s guidelines before applying any finish.

When This Matters

Colouring or painting is especially helpful when you want your models, prototypes or moulded objects to match a specific aesthetic or need to stand up to wear and exposure. If you require a robust, coloured surface finish for flooring, tiles, or driveable areas, a pigmented polyurethane coating like Prolux PU coating is available in a wide range of colours.

Related guides

How To Use Pu31 Resin

Whether you choose to colour your PU31 resin in its liquid phase or apply a painted finish after curing, always follow your product’s specific instructions for best results. For more details on using and customising PU31 resin, explore the full guide on how to use PU31 resin.