Oil Painting Mediums

Talk about myths! Oil painting mediums sure are mysterious. And confusing. And toxic. Or not. Brrr I’d stay away if I were you. And that is what I did when I first started using oil paint. I tried to keep things simple and just painted with paint and brushes. I learned that, most of the time, I did not need a medium. And that freed me up to learn about mediums slowly and in my own time. Because I was curious. My favourite art supplies store has more than 10 pages of mediums in their oil painting catalogue alone! Jeez, what is all the fuss about?

Disclaimer: Some of the links in this article are affiliate links. This means that I earn a small commission if you click through and make a purchase through these carefully chosen links. It will cost you nothing  extra and you would support this blog for which I would be most grateful. 

​What is a medium?

An oil painting medium is intended to change the way the paint naturally behaves. So if you want the paint (straight from the tube) to be more fluid, or more stiff, more glossy or quicker to dry, you can add a medium to your paint. You can also try a different paint brand, or a different pigment (see my blog post about brands for example) but generally artists use a medium to change paint characteristics.

What I use

And so in my early painting days (I sound really old now) I tried to add the odd drop of refined linseed oil to my paint and learned it made the paint more fluid and for some colours it slowed down the drying time. I quite liked that as I like to paint thinly and so more fluid paint allowed me to apply the paint thinly and sometimes more transparently. For many years that is the only medium (if any at all) that I used.

But going by the 10+ pages in the art materials catalogue there is so much more. So a few years ago I decided to learn about mediums and try out a few. I asked my fellow artists on Facebook what they used, what recipes they had, and I tried some out myself. For my lace painting I could do with a medium that made my paint very fluid, yet not transparent. After some discussion and recommendations I came up with a mix of refined linseed oil, solvent (I had low-odour solvent Sansodor in the studio so used that) and a little bit of stand oil. The mix was lovely for fine painting work and I used it a lot. I must admit, however, that I can’t be bothered to mix it anymore, and have gone back to good old linseed oil or simply nothing at all.

​I did, however, buy and try various other mediums, such as Roberson’s Glazing Medium, Graham’s Walnut Alkyd Medium, and Winsor & Newton’s Oleopasto. The glazing medium and the Oleopasto gave me a very strong physical reaction. Within minutes of adding it to the paint, I had to throw away the paints and my (disposable) palette to get rid of the fumes in my studio, fumes that made me feel very ill indeed. I still don’t know which ingredient exactly made me feel so bad and so now tend to stay away from toxic mediums and solvents in general. I am not a fan of turpentine either, as it makes my eyes water and my throat sting. Unfortunately, it is an ingredient in most mediums.

Artists Love Mediums

But I know many artists who swear by their mediums. Many of them find the one they like and stick to it for years. Have a look at Jackson’s recent blog post about mediums, and see what a variety of artists answered to the question which medium they liked the best. Jackson’s also asked me to contribute to that blogpost (thank you, Jackson’s!) which then became the inspiration for the post you are reading now.Well-known city painter Peter Brown, for example, swears by the aforementioned Roberson’s Glaze Medium! Haidee-Jo Summers prefers to only bring a low-odour solvent when painting out and about, although she does use and make a medium when working in the studio.

​Solvents

Solvents are not only used for cleaning brushes, but also used in mediums. It makes paint dry quicker and thins it. Use it too much and the oil in the paint will break down, leaving you to paint with just pigment which will not adhere to your canvas.

Just a Drop

It is important to only use little amounts of medium or solvent in your paint. I read somewhere you should never add more than around 20% of medium to your paint and that sounds about right to me. You must make sure you are painting with paint, not with medium. The medium is only added to change the texture and behaviour of the paint somewhat so tiny drops is really all you need.

Fat over Lean

The other important thing to remember is to paint ‘fat over lean’. This oil painting rule has caused a lot of confusion and fear amongst artists and I get emails asking me how painters should plan out their layers in order to stick to the fat-over-lean rule. I believe this rule has been allowed to dominate too much in painting practices and should be taken as a rule of using common sense. I wrote a blog post about it, encouraging people to not worry too much as long as you use common sense.

In short one should never seal in a slow drying paint layer with a fast drying paint layer. The slow drying layer will be sealed in by the dry top layer and will not be able to dry properly, causing all sorts of unpleasantries such as rippling and cracking.

​A Lof of Choice

If you think you need to use an oil painting medium there is a vast amount of choice. It helps to figure out what you are after. Whether you want your paints to dry quicker (remember the paint on your palette will too!!), or slower, be more fluid or more thick, more glossy or more matt, there is a ready-made medium for every possible effect.

Many artists, as was suggested before, prefer to make their own mediums with their own personal combination of solvent and oil. Linseed oil, solvent and stand oil are popular combinations.

Oils

There are many different types of drying oils on the market. They all increase drying time and fluidity. There is not only linseed oil (most popular and used in most oil paints), but also poppy oil, safflower and walnut oil (does not yellow as quickly, and is paler initially so good for light colours). Stand oil is a thicker (linseed) oil that evens out brush marks and increases gloss.

Turps

Traditionally turpentine was used for thinning paint and cleaning brushes. It is often mixed into a medium containing (stand) oil. Besides turpentine you can use a low-odour alternative such as Winsor & Newton’s Sansodor (a mineral or white spirit) which is less toxic than turpentine. Other alternatives are Gamsol, Roberson’s Studio Safe Solvent (It smells of oranges but must not forget it is still toxic), Zest it (not 100% safe either) and various other brands of low-odour solvents.

Ready-Mixed

With a drying oil and a solvent you can make your own medium very well. But many manufacturers want to save us the hassle and have come up with the most weird and wonderful mediums one can imagine. Some are so successful that many, many artists use it in all their work and have done so for years. To name a few popular ones: Winsor & Newton Liquin (speeds drying and comes in lots of varieties such as a medium for impasto; Oleopasto, Liquin Fine Detail or Liquin Light Gel), Michael Harding Oil Painting Medium (increases gloss and transparency ), Roberson’s Glaze Medium (for glazing transparent layers), Gamblin Galkyd Gel Medium (for thick brush marks), Maroger Medium (great for wet-in-wet painting), and many, many more.

Brands

Most paint brands will have their own mediums. Of course there is no need to match brands and you can safely use any oil painting medium with any brand oil paint.  Varnish is generally not considered a good option for use as a medium. Damar also has mixed opinions about its usefulness.

Trial & Error

As with everything it is a matter of trial and error and finding what works for you. For beginning artists I would strongly recommend to stay away from mediums until a much later stage. There is a real risk of using too much medium and producing unstable paintings if you are not careful. It also pays off to learn how paint behaves on its own before diving into making adjustments.

Back to Simplicity

After my little exploration of mediums I am back to simplicity. I have some refined linseed oil nearby but only use it if I need some extra fluidity. I have some solvent (low odour miniral spirit) nearby in case I need to thin the paint or clean out a brush. Both are generally kept in the cupboard and rarely come out.

If you are ready for it, do dive into the wonderful world of mediums and have a ball. You might find your perfect painting partner or you might go back home to familiarity. In either case; enjoy!

Further Reading:

• Jackson’s blog post about how various artists use mediums
• Useful tips about mediums on Cass Art’s website
• Winsor & Newton advises on some special effects with mediums

I hope you enjoyed this blog post. Do let me know your thoughts in the comments below. What is your favourite medium?

Read Next: Brushes