5 Reasons Why Oil Paint Won’t Spread

Oil paintings have long been synonymous with beauty and artistic brilliance. However, painting with oil paints poses unique challenges that new painters often struggle with. One of these challenges is getting the oil paint to spread without leaving patches or dull spots. 

Ideally, oil paintingsOpens in a new tab. should have a smooth, butter-like texture, as opposed to being gooey. If you want to spread it to help you achieve the effect you want, you must ensure it stays at the right consistency or that the surface you’re applying it on is suitable for it.

Here are 5 Reasons Why Oil Paint Won’t Spread: 

  1. The paint is too thick.
  2. The canvas isn’t primed.
  3. The paint is on an absorbent surface.
  4. There’s too much solvent.
  5. The paint has been applied too thinly.

Keep reading for an in-depth look into the causes of oil paint not spreading and what you can do to prevent this issue in the future. 

Causes of Oil Paint Not Spreading

In the right hands, oil paintings can look magnificent. You can see countless examples of these types of paintings throughout the centuries, depicting various subjects such as royalty, mythology, and others that strike the artists’ fancy. However, if you’re a beginner, you need to take the following steps to make sure you can make use of oil painting’s incredible properties.

The Paint Is Too Thick

The most likely reason that your oil paint is not spreading is that the paint is too dense. Some oil paints are rich in oil and can easily spread across a surface. However, other oil paints are thick and difficult to spread over a canvas. Keep this in mind when buying oil paints, as some are easier to use than others, especially for beginners. 

If the oil paint you’re using is too thick, there are home remedies you can use to dilute the paint. The easiest way to thin oil paint is by adding an even mixture of linseed oil and a solventOpens in a new tab.. This will allow you to spread it across a surface effortlessly. 

It’s essential that you only add a small amount of the linseed-solvent mixture to the paint at a time. Otherwise, you’ll make the paint too thin, posing an entirely different set of problems. 

If your oil paint and linseed oil mix end up becoming too thin, place the color on a wet cloth. The excess liquid should drain into the fabric, leaving you with a usable oil paint mix. 

The Canvas Isn’t Primed

If you’re painting on a relatively inexpensive or store-bought canvas, it’s likely not suitable for oil paints. Most canvases require treatment before oil paint can be used for them. The canvasOpens in a new tab. must be primed to absorb the oil paint and allow it to spread seamlessly across. 

To prime your canvas for oil painting, add a few layers of gesso to the surface. Gesso is similar to white paint that covers the entire canvas. You should also lightly sand the gesso between applications. Once your canvas has a couple of layers of gesso, it’s primed and ready for oil paints. 

If you don’t prime your canvas before oil painting, it’ll absorb too much oil causing the image to be dull. It’s also important to note that gesso gives painters a smooth surface that helps oil paint to spread across more easily. 

In case you don’t have gesso at home, you can also make a DIY mixture that offers the same results. To make gesso at home, Love Acrylic PaintingOpens in a new tab. recommends mixing three parts baking soda, three parts cornstarch, one part glue, one part white acrylic paint, and two to three parts water.

Alternatively, you can mix all of the above ingredients in any consistency until you have a spreadable mixture with no lumps.

The Paint Is on an Absorbent Surface

Not all painting surfaces react the same way to oil paint. Some of them are dry and therefore don’t absorb paints too much. Others (like claybord) will soak up a large amount of liquid from the paint, resulting in poor spreading or dull patches. If you want to use oil paints on an absorbent surface, you’ll need to prepare it first before you start painting.

To prepare a surface like claybord for oil paints: 

  1. Apply a thin layer of oil or alkyd ground to the surface. 
  2. Spread the oil or alkyd ground around with a trowel. 
  3. Use a foam roller to spread the liquid across the claybord evenly. 
  4. Set it aside to dry. 
  5. Once the claybord has entirely dried, it’s ready for oil paints. 

This process allows the claybord to absorb oils before you begin to paint. It also prevents the surface from absorbing all of the oil from your paints, making them difficult to spread. 

There’s Too Much Solvent

As I said earlier, you can use a mix of solvents and oil to thin out oil paint. But it’s also possible to use too many solvents to dilute your paint. When this happens, the oil paint will spread quickly but not look right. To prevent this from happening, spread the diluted paint over a damp cloth before you paint. 

Alternatively, you can mix the diluted paint with thicker paint to balance the mixture allowing you to spread it more easily and produce better results. Make sure you gradually add the thick paint (instead of adding it all at once) until you reach the consistency you want.

The Paint Has Been Applied Too Thinly

If you’re not using enough oil paint to cover the area you want to cover, you’ll have a hard time spreading it evenly. When the oil paint isn’t applied evenly, it’ll result in gaps and dull patches when it dries. This is especially true for paint with dark pigments like black or purple. Of course, the solution to this is to apply a layer of paint with the right thickness. 

Final Words

Oil paintings are beautiful and durable when done right. When they’re not done right, the result looks poor and dull — not to mention it doesn’t last long. There are many reasons oil paints don’t spread, like being too thick or thin, improper priming of the canvas, the canvas being too absorbent, and the presence of too much solvent. Fortunately, with the tips above, these problems are fairly easy to solve.

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Ines is a self-taught artist based in the UK. Originally from Caracas, she has dabbled in the world of arts and crafts in a diversity of ways participating in city intervention projects, sustainable practices’ open exhibitions, and her illustrations being featured in anniversary editions of literary magazines.

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