Best Paint Additive To Slow Drying Time For Oils And Acrylics

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Paint dries up quickly.

And it sucks.

This process happens especially quickly when you:

paint outdoors or on your balcony a lot
like to open your windows while working
live in a hot environment
the air in your room or studio is dry.

Either way – I feel your pain.

There you are, painting something, then you leave your palette for literally five minutes – and come back to completely dry pieces of paint. Isn’t it annoying?

Painting with that paint can lead to totally unwanted streaks and blobs of paint that cannot be blended. And it definitely doesn’t do any good to your work as well.

Luckily for us, there is an answer – paint additive to slow drying time.

Here are the 4 paint additives to slow drying time we will be covering today:

Sale

Winsor & Newton Painting Medium, 75ml (2.5-oz)...

Sale

Grumbacher Slow-Drying Medium II for Oil...

Liquitex Professional Effects Medium, 237ml...

Golden 0003580-5 8 oz Artist Colors Acrylic...

Why you need Paint Additives to slow drying time for Acrylics and Oils:

paint additives | paint additive products | art supplies equipment acrylic oil paint — You Can Save Me to Pinterest!

Additives that slow drying time of the paint, also known as retarders, are widely used for paints that dry quickly when exposed to air and cannot be as easily dissolved with water (unlike watercolor or gouache).

While both watercolor and gouache can be dissolved with water right on the painting surface and it doesn’t cause any problems if done carefully, it’s absolutely impossible with oils or acrylics. Once they’re dry, there is no way back.

Temperature, humidity, and airflow are the most important factors that influence the drying times of acrylic paint.

The most popular case of using retarders are with acrylic paints, that are well known for their fast drying and following inability to dissolve or mix with anything. Different additives to slow drying time are also used with paints like oil or tempera.

Yes, “slowing drying time of oil paints” may sound crazy to someone, since it’s a well-known fact that oil takes a very long amount of time to dry on canvas. However, oil paint that stays on the palette can dry relatively quickly, and some artists need to slow the process down when they paint their work in several phases within several days and want the paint to stay in a working condition.

Very hot and dry air makes paint dry even quicker, makes it either sticky and difficult to work with or absolutely unusable. It can always be a big and unpleasant waste of paint if it has dried while still being on the palette. You might have spent a lot of time mixing it, or there was simply a lot of it and now it’s all gone.

So, all paints need to be kept moist long enough to apply and manipulate it in the exact way and technique that the artist wants.

Alternatives

Of course, you can always add water to your acrylic paint to make it wetter. A little water can also help apply it more smoothly, especially on water absorbent surfaces.

But, unfortunately, this isn’t the most effective way, since water still evaporates relatively quickly and some paint formulas cannot be mixed with water (Read the information on the label before you try it!)

Another thing is that oil paints do not care about water at all, therefore it can’t be used as a retarder in that case.

There also are various options of palettes that are non-absorbent, such as plastic, porcelain or glass ones (and porcelain palettes are considered to be the best for acrylics), or even so-called Stay-Wet Palette, that keeps the paint wet. It has a layer of wet sponge under the acrylic film that you mix your paints on. And you can even make something like this palette yourself in case you can’t find or afford it.

Water-absorbent or water-holding agents (like glycerin) can also slow drying, but they have to be used carefully since they can leave unwanted residue and spoil your paint coverage and the outcome of your paint job.

Using Paint Additives

In fact, the most effective way to slow down drying time are paint additives, that are made specifically for certain purposes and paint types. They usually are a blend of several chemicals, predominantly glycols.

They evaporate far more slowly than water, they keep the polymers that paint consists of apart and therefore keep the paint wet and easy to work with.

Actually, adding a retarder to your paint won’t change the paint’s characteristics and might even make the color a little bit brighter and the paint itself more easy to spread.

The quantity of the retarder you decide to use will give different outcomes. It’s best not to add more than 25% of this additive to your paint, otherwise, it will produce bubbles while mixing, and the texture would be too heavy and thick to comfortably work with.

If the mixture is 1 part of additive to 4 parts of paint, it will make a great result, that will be easily and smoothly mixed and spread, and can be used with both brush and palette knife.

Retarders aren’t too effective in cases when the paint is spread in a thin layer on a very absorbent surface, but, most likely, nothing can help you in that particular situation.

You also need to take care of the environment you keep your paint in – humidity and coolness are the key. Otherwise, paint additives are the way to go.

Paint Additive To Slow Drying Time For Oil Paint

Paint additives for oil paints to slow their drying time are usually oils themselves.

The paints that are based on a clove or poppyseed oil are the slowest to dry, and you can always add some more poppyseed oil to your paint if you want it to dry even slower than it already does.

But there also are specific chemicals for that purpose:

Winsor & Newton Artists' Painting Medium

Best Paint Additive To Slow Drying Time For Oils And Acrylics

The medium is made to be resistant to yellowing and will definitely not affect your paintings’ colors in a negative way.

It reduces consistency a little bit, and overall improves the flow of oil paint.

It’s an additive that is perfect for fine details on your works, for glazing, for smoothly blended areas with no brush marks. It’s also suitable for oiling out and enriching dull patches of your works, if you need that.

+ It’s absolutely safe to use and non-toxic;
+ Will give you a rich, silky and sculptable mixture that is easy to apply with both palette knives and brushes;
+ Doesn’t dull the colors neither while wet nor after drying;
+ Blends in easily;

– You might experience some problems with the bottle itself and it may be difficult to open the cap;
– It might be not good to you if you are too sensitive to smells, because of its odor.

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Grumbacher Slow-Drying Medium

Another oil painting medium you can try out is Grumbacher Slow-Drying Medium. It will help you slow drying time and is perfect for working in alla prima (also known as wet on wet) technique.

It will provide you with a high gloss finish (and it’s up to you if it’s a bonus or a flaw depending on how you want your painting to look like in the end), and it can be used on dry paintings.

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Paint Additive To Slow Drying Time For Acrylic Paint

If you are working with acrylic paint, you will need other special products that work in a different way.

Watering the paint can lessen the opacity of the color or weaken the binder, so a better solution will be adding a retarder or a blending medium. An example of a great blending medium is:

Liquitex Professional Slow-Dri Gel

It’s a binder-free gel that contains slow-drying agents that will significantly (up to 40%) increase working time of your acrylic paints.

You’ll only have to mix it into the paint while it’s on the palette to slow the skinning-over of your paint and improve its blending time.

+ Doesn’t affect paint opacity when mixed;
+ Doesn’t make the paint layers crack after drying;
+ Can give your acrylic painting the style of an oil painting;

– Its consistency might make it a bit hard to mix in very smoothly;
– Might be messy, so don’t let it get anywhere except your palette.

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If the thing you are looking for is a retarder, try out this product:

Golden Artist Colors Acrylic Retarder Additive

It is useful in wet on wet techniques and reduces paint skinning on the palette very well. You can use it with other brands of acrylic paints.

It also dries up matte and doesn’t change any properties of your paint.

+ Will allow you to paint all day without worrying;
+ You will need a little of it, so one purchased bottle will last for a long time;

– It’s a gel – and some artists prefer liquid additives over gel ones;
– You will need to be extra cautious if you’re allergic and avoid excessive skin contact.

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Final Thoughts

Overall, the best way to understand what method and additive you like most is experience.

So don’t be hesitant to try out different liquids (or gels, or oils) to find out what you like most and what goes best with your own personal drawing techniques and your preferred paint brand.

Sometimes even ratings can’t help in choosing the best supply.

So, now that you know what can help you slow drying time of your paints, you can start experimenting bravely to get the best results.

Author: Hanna Martsynkevich
Hanna is an artist, poet and musician who lives in Minsk, Belarus. She loves food, cats, gigs and esoteric stuff. She posts the things she does on Instagram and sometimes appears on FB.