How do you make thin oil?

To make thin oil, especially for use with oil paints, you can create a thinning medium using mineral spirits.

Here's how:

1. Combine Ingredients: Add approximately 2 tablespoons (30 mL) of mineral spirits to a jar.
2. Stir Thoroughly: Use a palette knife or similar tool to thoroughly mix the mineral spirits and a drying oil together. Walnut oil is a commonly used drying oil, but other drying oils will also work.
3. Store Properly: Transfer the resulting thinning medium to a small, airtight glass container for storage.

The mineral spirits reduce the viscosity of the oil, creating a thinner consistency ideal for glazing techniques or creating smoother paint application. Using a drying oil such as walnut oil helps maintain the binding properties of the oil paint.