Oil Varnishes

How to successfully varnish an oil painting

First, choose a dust-free area where you can keep windows and doors closed. It’s best practice to varnish on a flat table or work surface – avoid working vertically.

Before you start varnishing, gently wipe the surface of the painting with a lint-free cloth to remove dust. Then stir the varnish well and pour it into a clean, flat saucer or tin. Load your brush, then wipe it on the side of the saucer so it’s not dripping.

Using long, smooth brush strokes in one direction, cover the painting in a thin coat, then turn it 90 degrees and use the same long strokes across the wet first coat to ensure an even covering. Make sure to only apply one layer of varnish like this, or the result will be patchy.

Avoid going back over areas that you’ve done. If there are spots you’ve missed, simply allow the piece to dry completely and revarnish.

After you’ve finished, ensure that you shield the work from dust while it dries, using a protective plastic cover known as a tent.

Which varnish should I use for oil painting?

Choosing the right varnish often comes down to personal preference and the final finish you want.

Common varnish types:

Dammar Varnish: High-gloss, traditional choice. Use Distilled Turpentine to remove.

Gloss Varnish: Enhances deep, bright colours but creates reflections. Requires stronger solvents for removal.

Matt Varnish: Reduces glare but dulls colours. Easier to remove.

Satin Finish: Can be achieved by mixing gloss and matt varnish 50/50 or using a dedicated satin varnish.

Retouching Varnish: A temporary gloss coat used for recently completed works. It allows for continued painting and should be followed by a permanent varnish after the painting has fully dried.

How many coats of varnish does a painting need?

The number of coats depends on your chosen varnish and desired finish. For most varnishes:
- Apply 1–2 coats of matt or satin varnish to avoid cloudiness.
- Apply up to 3 coats of gloss varnish for added depth.
- With spray varnish, you can apply up to 50 coats for an ultra-glossy look, though 2–3 is usually sufficient