How to Do a Wash on a Scale Model: Technique, Products and Mistakes to Avoid

A wash is a weathering technique that consists of applying a heavily diluted product into the recesses, panel lines and raised details of a painted model, to enhance the depth and realism of the surface. It is one of the first weathering techniques to master after the base coat.

Enamel wash or acrylic wash: what should beginners choose?

The Humbrol Enamel Wash Black is an enamel wash, as its name states. It is a common choice for beginners because its working time is generally longer than an acrylic product.

The ACRYLIC WASH Afrika Korps Wash by AMMO by MIG Jimenez is an acrylic wash in a 15 ml bottle: the product page states it is applied with a brush and can be thinned with a few drops of water to adjust the intensity of the effect.

The AK Interactive Wash and Vallejo Wash FX ranges each offer a wide colour chart. Before using them on a visible part, always check the dilution and cleaning instructions on the packaging, and test the product on a spare part or hidden area first.

To go further into the differences between paint brands and ranges, see our guide AK vs Ammo vs Vallejo.

Preparing the surface before applying a wash

A wash is applied after the base coat, once it is fully dry. A layer of gloss varnish before the wash helps the product flow by capillary action into the panel lines and limits unwanted marks on flat areas. Our guide Scale model painting: complete method details the sequence of primer, paint layers and weathering steps.

Step-by-step application

1. Thin if needed: some products are ready to use, others are thinned with a few drops of water or thinner depending on their formulation. Our guide Which thinner to choose helps you pick the right one for your product.
2. Apply with a fine brush along panel lines, rivets and corners, letting the product spread by capillary action.
3. Let it set until the product has taken hold without being fully dry, following the manufacturer's instructions on the packaging.
4. Wipe off the excess with a slightly dampened brush or cotton swab, always in the direction of the panel lines, so the product only remains in the recesses.

Choosing the wash tone for your model's theme

Some references are designed for a specific theme, which helps you choose a tone consistent with your model's subject:

• WASH FOR AIRCRAFT ENGINE (AK Interactive) for aircraft engines.
• GREY WASH FOR KRIEGSMARINE SHIPS (AK Interactive) for warships.
• WASH FOR WOOD (AK Interactive) for decks and wooden elements.
• Mecha Color: Light Rust Wash (Vallejo) for mecha/gunpla-type models.

Protecting the result with a finishing varnish

Once the wash is fully dry, a matte or satin varnish protects the achieved effect and evens out the finish before any additional weathering steps (pigments, dry-brushing).

Common mistakes to avoid

• Applying a wash directly on a matte paint without an intermediate gloss varnish, which makes the flow uneven.
• Wiping off the excess in the wrong direction, against the panel lines.
• Waiting too long before wiping, risking permanently staining the surface.
• Using a solvent that is not suited to the product type without checking the manufacturer's instructions.
• Not testing the product on a spare part before applying it to the model.

Frequently asked questions

Do you need a gloss varnish before a wash? In most cases, yes: it helps the product flow into the panel lines and limits marks on flat surfaces.

Can you use an enamel wash over acrylic paint? This is common practice when the acrylic layer is protected by a varnish, but it is recommended to always test on a hidden area first.

Which tone should you choose for a first try? A dark tone (black, brown or dark grey) over a light base makes the effect easy to see and is a good way to practice the wiping motion.