Why Does Your Watercolor Paint Stink?

Example of an old watercolor

Most artists love buying lots of different paint palettes to build their collections. In case you’re the same, you will discover that your paints will start smelling weird… and even stink at some point. 

You’ve come to the right place if you’re struggling with the question, why does my watercolor paint stink. We know how stressful it can get if your beloved paint palettes smell bad and you’re confused about what to do with them. That is why in this discussion, we’ve covered all about malodorous paints, paint expiration, and how you can deal with moldy paint.

If you’re interested in finding out why your watercolor paint has a stench, stay with us till the end.

Why Does Your Watercolor Paint Stink?

Some paints may have a characteristic smellOpens in a new tab. within them. But paints like ultramarine blue, raw sienna, etc., do not bear any smell. If you noticed a funky smell within your paints, there might be something wrong.

So, why is your paint emitting a bad smell? Well, there could be a few different reasons. Let’s have a look

Loss of Quality

The most common reason your watercolor paint smells bad is that it has lost its quality or has become sensitive over time. It is a common problem when you have a lot of paint palettes, and you end up forgetting to reach out for some of them for a long time.

When your paints have not been used for a long time, the gum Arabic can detach from the pigments, and the paints smell bad like odor resembling that of chemicals.

Build-up of Gas

If you have unopened tube paints lying around for a long time, a common phenomenon is the build-up of gases. 

So, when you finally open the tubes after a long time for a painting session, the paint smells like a fart, and you can hear bubbling sounds when you squeeze the pigments out. The trapped paint explodes out in the open and looks dark.

Mold Formation

Your paints can also smell bad when mold and fungus have developed within the tube and pan.

Watercolor paints have a lot of moisture, which attracts mold, fungus, and mildew. Some paints also have additives and preservatives that often invite fungus. When mold develops within the paints, the paint smells like dung. 

When Do Watercolor Paints Expire?

Watercolor paints will not expire if they are stored properlyOpens in a new tab.. But without adequate care and storage facilities, there’s a chance that your paints will go bad and start stinking.

So, when do these paints expire? The expiration date for paints depends on whether they’re in a tube or a pan. Let’s have a look at when these paints expire –

Watercolor Pans

Watercolor pan paints will last you for almost a decade if stored properly. They can last longer if you allow them to dry completely before closing the lids. That is why artists love using pans for their fine paintings. Fresh paint pans are the best choice if you want the most long-lasting watercolorsOpens in a new tab..

Tube Paints

Compared to pans, the longevity of watercolor tubes is quite low. With proper storage facilities, tube paints can last as long as 3-5 years. Tube watercolor paints dry down within the tubes whether you open them once in a while or not.

Watercolor tubes can be salvaged using a few techniques. On the other hand, mediums like oils and acrylics cannot be salvaged once they’re dry.

If you want to read more in detail about the shelf life of tubes, you can read our article on How Long Do Watercolor Tubes Last?Opens in a new tab. Or, if you want to know more about the expiration date of watercolors as a general topic, this article on Does Watercolor Paint Expire?Opens in a new tab. would be a good read as well.

How to Deal with Moldy Paint?

A common issue with watercolor paints is mold development. But why does mold form within watercolor paints? As we’ve discussed earlier, dark mold grows wherever there is moisture. With watercolor paints, there is no scarcity of moisture.

Moreover, watercolor paints come with additives like Sennelier Aquarelle, which gives brilliance and luminosity to the colors. This additive is responsible for attracting mold, mildew, and fungus. You can face the same problem with honey and honey like additives. As a result, your watercolors start to smell funny over time.

So, how can you deal with it?

The first thing you can do about moldy watercolor paints is discarding them. If only one or two paints of the palette have developed mold, you can discard the affected colors. If the mold has spread to almost the entire palette, you have to let go of all the colors of the palette, unfortunately.

Another thing you can do is to abrade off the moldy part of the watercolor paint with scrap paper and use the remaining portion. Make sure that you wear gloves when you’re scraping the paint off. You can also try using a few drops of alcohol in your remaining paint to kill any surviving mold.

Pay attention so that none of the colors have any remaining mold spores. Otherwise, the spores can transfer to your painting, and your painting may get ruined too.

How to Prevent Mold?

Now that you know how a moldy paint can affect your painting, let’s have a look at some of the measures you can take to prevent mold formation in the first place –

Avoid Paints with Honey

Try to buy paints after going through the entire ingredient list. If you see honey in the ingredient list, it’s better to avoid purchasing that watercolor paints. Honey attracts mold, mildew, and fungus, so it’s best to stay away from buying such paints. 

Especially if you live in humid climates, honey can act as a precipitating mold ingredient for your paints. Honey encourages the paints to stay wet for a long duration, leading to mold development and a bad smell.

Use Premade Pans

Squeeze out watercolors from tubes and add them to plastic pans or palettes for making premade pans. When you make your own premade pans, you can take better care and store them properly.

You can also use them with little water and make sure that they dry down completely. In this way, you can prevent any mold or mildew formation in your pans. 

Store in Low Humidity Areas

Highly humid areas attract mold and fungus. That is why it’s best to store your paints in low humidity areas. You can find low humidity areas in your house wherever there is air conditioning. 

If you have dehumidifiers in your home, you can store your watercolors near them. Continuous exposure to dehumidifiers or low humidity is completely safe for watercolors and will help prevent mold formation in your paints.

Do Not Cover Wet Paints

Another hack you can try to prevent mold formation is not covering your wet paints. Wet paints are full of moisture, which is why they invite all sorts of things like fungus, mildew, and mold. 

The best thing you can do to protect your paints from mold is to let them dry completely and close the lids. Excess water within the pigments can attract mold.

No matter how long it takes, make sure they have dried down well. If they are closed without adequate drying, there’s a strong chance of mold development within the watercolors.

Emma Jane LefebvreOpens in a new tab.

Final Words

Why does my watercolor paint stink? Most likely, your paints have gone bad or formed mold and fungus. Try opening your paints once in a while and store them in proper spaces to protect them from going bad and stinking. 

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Ines, a self-taught artist from Caracas now based in the UK, explores diverse forms of art, from unconventional materials to sustainable and responsible use of resources.

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