Mediums and Varnishes for Oil Painting

Oil Painting Mediums and Thinners

You rarely paint with oil paints straight from the tube. Thinners, oils, mediums, and varnishes give you control over consistency, gloss, and drying time. They help you build a painting correctly, layer by layer, and protect it with varnish when you’re done. We offer trusted brands of oil paints and accessories.

What You Need for Oil Painting

• Thinners – turpentine and odorless thinners for thinning paint and washing brushes
• Oils – linseed, safflower, and walnut oil for gloss, flexibility, and slower drying
• Mediums – fast-drying and painting mediums for adjusting consistency
• Varnishes – damar final varnish to protect your work and give it a uniform gloss

How to Use These Products

Follow the “fat over lean” rule: thin the lower layers with turpentine and add more oil to the upper layers. Oil gives a layer gloss and flexibility, while medium speeds up drying. Once the painting is fully cured, apply final varnish to protect it from dust and UV radiation.

Who This Category Is For

This category is for anyone who paints with oil paints and wants full control over their technique. Beginners only need turpentine and linseed oil, while advanced painters can put together their own set of mediums for the effect they want. You’ll find brushes and palette knives in the brushes category.

Frequently Asked Questions

What do you use to thin oil paints?

Most often, turpentine or odorless thinner, which thins the paint and also cleans brushes. Add oil instead of thinner to the upper layers so they stay flexible and are less likely to crack. Use thinner in a well-ventilated room and follow the “fat over lean” rule.

What are linseed, safflower, and walnut oils used for?

Oils give paint gloss and flexibility and slow drying, giving you more time to mix. Linseed oil is the most versatile, but it yellows slightly, so safflower or walnut oil is a better choice for light shades. They stay clearer. Add them a drop at a time to keep the layer from becoming too oily.

When and how should you varnish a painting?

Apply damar final varnish only after the painting has fully cured. With oil painting, this can take several months. Varnish evens out the gloss, revives the shades, and protects the work from dust and UV radiation. Apply a thin, even coat to a clean, dry surface.

What is the difference between medium and thinner?

Thinner, such as turpentine or odorless thinner, only thins the paint and gradually evaporates. Medium remains part of the layer and changes its properties, adjusting gloss, adhesion, or drying time. To start, a combination of thinner and linseed oil is enough. Add other mediums to suit your technique.