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Why is My Oil Paint Not Drying?

why is my oil paint not drying

The great thing about oil paints is that they do not dry as quickly as acrylics, thereby allowing you to mix colors straight on the canvas. However, some paints take so long that even after days have passed, the painting is still not dry enough for display.

Why is my oil paint not drying? There might be a couple of reasons why it is not drying fast enough. This article will discuss the different causes and how you can fix them.

Top Reasons Why Oil Paint is Not Drying

The important thing that you need to know about oil paints is that they do not “dry” in the same sense as water-based paints. Because they do not contain water, oil paints polymerize or turn into semi-solids. This does not happen overnight or even after a week.

Most of the time, you will be waiting up to a year before an oil painting is dry enough to put inside a glass frame. You cannot even apply fixative to an oil painting that is not completely dry as it will smudge the paint.

Aside from the inherent properties of oil paints, there are other reasons why your oil paints are not drying at all.

You Used Water to Thin Your Oil Paints

If you are a beginner, and no one told you, you should never use water for thinning oil paints. This might seem to work at first but it is still possible for them to separate later. If the water separated and it ended up under the oil paint, it will take a longer time than usual to dry.

Even if you did not use water to thin the paint, washing your brushes without drying them properly can also cause the problem.

Environmental Factors

Also, this might be the case if it gets humid in your location, especially during the summers. The extra moisture in the air might have contributed to the paints not drying quickly. This is not usually the case but it is certainly a possibility.

In addition, the room where you are drying the painting also needs to have proper ventilation. The oil paints will start to polymerize when exposed to air. This means the oil paints will dry faster if there is excellent air circulation in the place where you store them.

The Colors of the Paints

Oil paints dry at different rates depending on what colors you use. Some pigments have thicker consistencies, thus making their curing time exceptionally long. This is why you should plan and think of the types of colors that you will be using.

For instance, oil paints with earth tones typically contain iron oxide, which makes them dry faster than the other colors. Also, some brands of oil paints make use of cobalt, which also makes the paints cure quickly.

If you are pressed for time, you should avoid using deep blacks, bright whites, and yellows. If you need black, you can just combine different colors to achieve it.

The Thickness of the Paint Layers

If you used a pallet knife to apply the oil paints, the paint layers will be quite thick. Since oil paints cure starting from the surface down to the internal layers, it will take a whole lot longer to dry compared to when you use thin layers.

The Medium Used

Artists often use a separate medium to not just thin the oil paints but also make them dry faster. Most of the time, the medium used is a type of oil. If the oil is a bit too thick, it will also retard the drying process.

In many cases, you will need to wait weeks, or maybe even months for the oil paints to dry. Only then will you be able to seal the painting and place it behind glass.

However, there are ways to significantly shorten the drying time.

How Can You Speed Up the Drying Time of Oil Paints?

how long does oil paint take to dry

If you don’t want to wait up to a year for your oil painting to dry, here are some tips that might help.

  • Leave your finished painting in a room with ample ventilation and receives enough natural light – If the place gets a bit too humid, consider getting a humidifier. Open the windows but leave the bug screen down. This is to provide more ventilation without risking getting dust and debris on the painting
  • Before painting, use a gesso layer or primer on the canvas – This will make the painting surface more porous, allowing the oil paints to adhere better
  • Use acrylics for the undercoats – If you are working on a commission, and you have a short deadline, it would be best to use acrylics for your base coat. For instance, if you are painting a landscape, paint the sky and background using acrylics. Use oils for the foreground
  • If it is sunny outside, let your painting dry in the sun – However, avoid doing this during the summer as the heat might be too much for the oil paints. This was how the old masters dried their paintings, so it should also work for you
  • Paint using thin layers – The thicker the oil paint layers, the longer it will take to dry. Use thinner brush strokes and allow the previous layers to dry before applying the next. This might make the painting process a bit longer, but it is better than waiting for months before you can frame your work

What Can You Add to Your Oil Paints to Make Them Dry Quicker?

Although they are a bit expensive, alkyd mediums can speed up the drying time of your oil paintings. Instead of weeks or months, the resin additives in alkyd mediums can reduce the drying time to just hours.

Aside from making oil paints dry faster, alkyds also give your work a glossy finish. This means you no longer need to add oils or solvents to make the dried paint shine.


Why is my oil paint not drying? You are not the first person who wondered that. Oil paintings are notorious for their long curing times. Some paintings have been drying for years and are still not dried enough that you can frame them without smudging the paint.

However, there are ways that you can shorten the drying time considerably. You can change a couple of things during the painting process or use additives to hasten the drying time. If the long drying time is the reason why you are not that keen to try oil painting, this article should have convinced you otherwise.