Most water-mixable oil painters use mediums to increase the flow of their paints instead of water and only use water to clean up – I like to think of water-mixable oils as water-washable oils. There are also mediums for extending, thickening, and increasing or decreasing the drying times of the paint. Continuing our series on water-mixable oils this article takes a look at how important mediums are for this paint. The earlier article answers questions about the paint itself Water-Mixable Oils: Vibrant Colours, Easy-Cleanup and They Needn’t be Sticky. I hope you will find these two articles useful as a guide to water-mixable oil paint and painting mediums.
The Wide Variety of Water-mixable Oil Painting Mediums
At Jackson’s, there are six water-mixable oil (WMO) brands that each make a selection of mediums to modify your paints in various ways. The most often used medium is ‘painting medium’ which extends the paint, makes it more fluid and allows it to flow more smoothly off the brush. There are paste or gel mediums that allow you to thicken the paint or to increase transparency or extend it without losing body. There are mediums formulated for glazing techniques and mediums to accelerate drying. Water-mixable linseed or safflower oils can be added to paint to increase flow and slow drying, or they can be used as ingredients when making your own water-mixable mediums. WMO mediums come in fairly small bottles or tubes, but it takes very little to get the paint to flow smoothly. A general rule in all oil painting is to only use as much medium as you need to get the modification you want – excess medium could make the paint too oily and can cause drying problems or wrinkling. For this article, I have mixed a wide variety of water-mixable oil mediums with paint to find out the characteristics of each one and how they are best used.
Contents
- Characteristics of the Different Makes of Water Mixable Oil Mediums
- Painting Mediums
- Impasto Mediums
- Fast Drying Mediums
- Slow Drying and Glazing Mediums
- Fat-over-lean
Water-mixable oils and mediums are referred to by a few names but they all mean the same thing: watermixable, water-soluble, water-miscible, water-reducible, WMO, and aqua oils. Below is a list of all water-mixable oil mediums currently available at Jackson’s, by brand:
Winsor & Newton Artisan
- Painting Medium
- Fast Drying Medium
- Impasto Medium
- Thinner
- Linseed Oil
- Safflower Oil
Holbein Duo Aqua Oil
- Painting Oil Medium
- Quick Drying Liquid
- Quick Drying Medium (paste) in Gloss and Matt
- Linseed Oil
- Linseed Stand Oil
Talens Cobra
- Painting Medium
- Quick Drying Medium
- Paste Medium
- Glazing Medium
Grumbacher Max
- Quick Dry Medium
Daniel Smith Water Soluble Oil
- Painting Medium
- Fast Drying Medium
- Transparent Blender
- Linseed Oil
- Fast drying Linseed Oil
- Safflower Oil
Schmincke
- Medium W
- Medium W Gel
These can be mixed with conventional oil to make it water-mixable. Can also be used as a glazing medium and slow drying medium for WMOs.
M. Graham Walnut Alkyd Oil Medium
This is not a water-mixable oil medium. I’ve included M. Graham because it is a favourite of WMO painters and it is so fluid that you use very little which then doesn’t interfere with the water wash-ability at all.
Note: I have recently had Gamblin’s Solvent-free Gel recommended as a good medium for WMO, even though, like the M. Graham, it is not water-mixable itself. Because you use so little the water-washability is not affected. Since it was after these tests were done, it is not included in them, but I wanted to at least mention it.
Characteristics of the Different Makes of Water Mixable Oil Mediums
To find out more about the mediums I grouped them into four types based on the modification you might want to achieve with your paint:
1. Painting Mediums – to increase flow, make more fluid
2. Impasto Medium – to thicken the paint or to increase transparency and extend the paint while not losing too much body
3. Fast Dry Mediums – to speed up drying
4. Oils and Glaze Mediums – to slow down drying, extend paint, increase transparency, increase fat for final layers, for glazing
Testing Method
I made a chart for each of the four groups of mediums. Many water-mixable oil painters like to use M. Graham Walnut Oil Alkyd Medium, which is not a water-mixable medium, but since you use so very little it does not interfere with the water-washability at all. So I added it to all the tests. I also added mixing with just water and neat paint for a baseline comparison.
I mixed the mediums with two brands of paint that have quite different characteristics: Jackson’s Aqua Oil because it is sensitive to water-seizing, it is buttery-stiff so needs a medium to make it flow more and it dries nearly matt with no tack; and Daniel Smith Water Soluble Oil because it is not very sensitive to water-seizing, is buttery out of the tube so only needs a little help to flow and dries glossy and tacky. All tests except the impasto are 10 parts paint to 1 part medium, the impasto mediums were mixed in a 50-50 ratio. They were all mixed on a palette and then applied to the chart panel. The application was in three thicknesses: a thick patch with a palette knife, then a stripe with a loaded brush, and a stripe with a drier brush for a thinner layer. The drying times listed are for the thinnest layer being touch-dry, unless I state otherwise. The colour is Ultramarine Blue. The panel is a Jackson’s Premium Cotton Canvas Art Board.
The General Findings
Because it takes so little medium to modify the paint, you don’t lose the characteristics of the paint. The paint to which you add the medium will be a main factor in the resulting mix. If the paint is fast-drying or matt or fluid – those characteristics will remain and have a big effect on the results. So the same medium mixed with different paints will behave differently.
All the brands of mediums mix fine with other brands of paint. I mixed and matched brands in my earlier tests and this remained true. But some make particularly good pairings, like Cobra Quick Dry Medium with Jackson’s Aqua Oil, Artisan Painting Medium with Daniel Smith, and M. Graham Walnut Oil Alkyd with Jackson’s Aqua Oil. Though they all work with other brands it is possible that they work best with their own brand. I know there are at least three ways to modify linseed oil so that it will emulsify with water, so if you mix brands that use different methods, there might be a slight difference in some cases. But in most cases, they worked very well.
Water-mixable oil mediums are compatible with conventional oils but will not make them water-mixable because you don’t use nearly enough. Only the Schmincke Medium W, used in a ‘one part medium to two parts oil paint’ ratio, will allow conventional oil paint to become water-washable.
I checked odour because some artists choose to use water-mixable oils because they are sensitive to the odours associated with traditional oil painting. I found that some of the water-mixable mediums have a strong chemical smell while some have a mild linseed oil smell. You will see those results in each section.
Painting Mediums
These are extenders that allow the paint to flow more.
- Artisan Painting Medium
- Holbein Painting Medium
- Cobra Painting Medium
- Daniel Smith Painting Medium
- M. Graham Walnut Oil Alkyd
Washability
Adding Painting Medium to the paint helped with its washability. All brushes, even M. Graham (not water-soluble), rinsed out well without soap except Artisan which needed a bit of soap.
Odour
Artisan – fairly strong chemical smell like formaldehyde
Holbein – slight chemical smell and linseed smell
Cobra – mostly a light linseed oil smell
Daniel Smith – mostly a light linseed oil smell
M Graham – mostly a light oil smell

When I washed the pipettes that I had used – the four that I used with the water-mixable mediums turned milky as they became emulsions with the water, and as expected, the M Graham did not as it’s not water-mixable. It just reminded me that these are indeed different, so I thought I’d share it.

Painting Mediums left to right: Artisan Painting Medium, Holbein Painting Medium, Cobra Painting Medium, Daniel Smith Painting Medium, Graham Walnut Oil Alkyd. An odd finding was that the Holbein Painting Medium is very fluid or has no surface tension – the one drop spread very far when it was dropped onto the palette while the other four brands stayed as drops. Though you will see in the test results that it did not make the paint more fluid, when mixed with paint it was stickier than the others.
Painting Mediums mixed with Daniel Smith
- All five brands mixed in easily, the paint sort of melted into them.
- Artisan and Cobra had the smoothest flow.
- Holbein was a bit sticky, a little harder to brush smoothly.
- As expected, water was harder to mix in than the mediums were, but flowed fine (and dried more matt).
- As expected, neat paint flowed the least as it was still thick.
Painting Mediums mixed with Jackson’s Aqua
- They all created a lovely smooth flowing mixture.
- M. Graham flowed the most.
- Holbein flowed least of the five with both paints, but it wasn’t bad. It was just surprising since it is the most fluid. Maybe it is more like a thinner than an extender.
- The 1 part medium to 10 parts oil paint (1:10) significantly increased the transparency of the Aqua paint.
The Gloss of the Painting Mediums
Daniel Smith water-mixable paints are glossy on their own. All the painting mediums except for Holbein, when mixed with Daniel Smith made the paint even glossier.
Jackson’s Aqua water-mixable paints are satin-matt on their own. Daniel Smith and M. Graham mediums, when mixed with Jackson’s Aqua paint, made the paint glossier. Artisan and Cobra made it slightly glossier. Holbein didn’t change the natural sheen of the paint.
Changes in sheen are probably an indicator of the combining of the different emulsifiers used in each brand.
But, remember that surface sheen doesn’t matter much if you are varnishing, and varnishing is always recommended. You can read more about sheen and varnishing in this earlier post Water-Mixable Oils: Vibrant Colours, Easy-Cleanup and They Needn’t be Sticky.
Drying Times
Time until the thinnest paint layer was touch dry
- Painting medium mixed with Daniel Smith.
Cobra, Daniel Smith and M. Graham 1-2 days.
Artisan, Holbein (also the water and neat sample) 3-4 days. - Painting medium mixed with Jackson’s Aqua Oil.
The same drying times as Daniel Smith except they were all one day faster.
Summary
Impasto Mediums
- Holbein Quick Drying Medium (paste)
- Cobra Paste
- Daniel Smith Transparent Blender
- Medium W Gel
Odour and texture
- Daniel Smith transparent blender = low smell
- Cobra paste = low smell. The thickest and firmest, had the highest peaks. Lovely, jewel-like and very smooth. The only one that was as thick as paint.
- Duo quick dry medium (paste) gloss = medium smell. Sticky like stringy honey.
- Schmincke Medium W gel = medium smell, very smooth, melts into paint. It is thixotropic, meaning it becomes a more thin consistency when you move it about and brush it, and then it thickens up again when it sits still.

Four impasto mediums plus neat paint. Mixed 50-50. This image is right after painting, while it was still wet.

Although Holbein Quick Drying medium is a paste that comes in a tube, it is quite soft and doesn’t give any impasto texture. But if you want to add a fast-drying quality without losing too much body, this might be good for you.
Brush cleaning after using the impasto mediums
Info for both brush rinsing between colours in only water and final brush washing with Jackson’s Marseille soap.
All four impasto mediums when mixed with Daniel Smith paint made the brush harder to rinse than with just neat paint, but washing was rated good.
All four impasto mediums mixed with Jackson’s Aqua paint were easy to rinse out and super easy to wash.
Impasto Drying Times
A thin layer of neat paint took 3 days to dry in both paints.
- Holbein Quick Dry (paste) sped up the drying time of the paint by a day.
- Schmincke Medium W Gel didn’t change the drying time of the paint.
- Daniel Smith Transparent Blender didn’t change the drying time of the paint.
- Cobra Paste slowed down the drying time of the paint.
Summary
Fast Drying Mediums
- Artisan Fast Drying Medium
- Artisan Thinner
- Holbein Quick Drying Liquid
- Cobra Quick Drying Medium
- Max Quick Dry Medium
- Daniel Smith Fast Drying Medium
- Graham Walnut Oil Alkyd
Odour
- Artisan Fast Drying: strong formaldehyde
- Artisan Thinner: spirits, slightly citrus
- Duo Quick Drying Liquid: slight chemical
- Cobra Quick Drying: linseed oil smell
- Max Quick Dry: moderate smell like curry powder
- Daniel Smith Fast Drying: linseed oil smell
- M. Graham Walnut Alkyd: mild oil smell
Fast-drying mediums mixed with Daniel Smith
Holbein mixture was sticky like thick honey not flowing.
Thinner is oily not like a solvent.
All had good flow except Artisan Fast-Drying medium and Duo Quick dry liquid. Which were thick and sticky.
Brush Washing
Artisan Fast Drying Medium, Artisan Thinner, Holbein Duo Quick Drying Liquid, Daniel Smith Fast Drying Medium, M. Graham Walnut Oil Alkyd – brush rinsing was moderate, washing was easy.
Cobra and Max – brush rinsing was poor, washing was easy.
Drying times
All brush marks were dry in less than 24 hours except for the Thinner.
With Holbein Duo Quick Dry – a thick layer was dry in one day.
All the rest a thick layer was not dry in one day.
Fast-drying mediums mixed with Jacksons Aqua
- Artisan Thinner changes the colour, it is lighter temporarily. It mixes in easily, is not thin like a solvent.
- Cobra and Max and Artisan Thinner flow beautifully.
- Cobra has the most flow it is lovely
- Max flows but has more body
- Cobra Quick Dry Medium and Jackson’s melt together particularly well.
- Artisan Fast-Drying didn’t flow much.
- Daniel Smith flowed but was a bit thicker like Max.
- Graham was great with both paints.
Brush Washing
For rinsing, all rated ‘good’, except Duo and Cobra rated ‘moderate’.
All 7 washed ‘easy’.
Drying Time
All thin and all thick layers were dry in one day.

Winsor and Newton Thinner is the droplet in the middle. It is not thin like a solvent. It is oily and really nice.
Notes
- It makes sense that Grumbacher Max would make a Quick-dry Medium as their paint is the slowest drying water-mixable oil. Max has two important notes on the bottle: 1. Apply in thin layers and allow to dry between coats. 2. Do not pre-mix medium with water prior to blending with paint.
- I liked the Artisan Thinner a lot. Because of the name, I thought it would act like turpentine and be a solvent that dried quickly, but it was oily with body and didn’t dry quickly. I put it in this group for the tests but I now consider it to be a painting medium, to be added for flow. So I have moved it to the Painting Mediums group in the summary chart.
- Holbein needs a good shake until it forms a cloudy emulsion. That means it contains water, but so does the Cobra which doesn’t need shaking, so there is something different in their makeup.
Summary
Slow Drying and Glazing Mediums
- Holbein Linseed Oil
- Cobra Glazing Medium
- Daniel Smith Fast Drying Linseed Oil
- Medium W
- M Graham Alkyd
They all had a similar viscosity.
They all melted into the oil paint, with Cobra and M. Graham doing especially well. Much easier to mix into the paint than water was.
Holbein Duo Linseed Oil was the least flowing off the brush.
Holbein Duo Linseed
Nice oil smell
Mixed with Daniel Smith – brush rinsing was poor, washing was easy.
Mixed with Jackson’s Aqua – brush rinsing was good, washing was easy.
Cobra Glazing Medium
Mild odour
Mixed with Daniel Smith – brush rinsing was poor, washing was easy
Mixed with Jackson’s Aqua – brush rinsing was very good, washing was easy
Daniel Smith modified linseed oil
Linseed oil smell
Mixed with Daniel Smith – brush rinsing was poor, washing was easy
Mixed with Jackson’s Aqua – brush rinsing was poor, washing was easy
Medium W
Mild odour
Mixed with Daniel Smith – brush rinsing was good, washing was easy.
Mixed with Jackson’s Aqua – brush rinsing was good, washing was easy.
M Graham Alkyd
(remember, this one is not water-mixable)
Linseed oil smell
Mixed with Daniel Smith – rinsing was very poor, washing was easy
Mixed with Jacksons Aqua – rinsing was very poor, washing was easy
Drying times:
A very thin dry-brush layer was dry in:
1 day: Medium W mixed with Daniel Smith and M. Graham mixed with both paints
2 days: Medium W mixed with Jackson’s, Duo mixed with Daniel Smith, Daniel Smith oil mixed with both paints.
3 days: everything else.
Summary
The Fat-Over-Lean Principle
If you paint in layers, letting each layer dry to the touch, then you will want to stick to the fat-over-lean rule to create a stable painting. You would start with the leanest medium mixture in the lower layers and end with the oiliest for the top layer. You can make a water-mixable medium leaner by adding water to it. Cobra Painting Medium is half water already. Cobra Glazing medium in the same as their Painting Medium but with no water. So by starting with a mixture of a lean medium and water, then moving to just the lean medium and ending with the oily medium with no water, you can control how much oil is in each paint layer and be sure that each layer is more flexible than the layer underneath. If on the other hand, you are painting your whole painting in one sitting or in a couple of days where no layer dries while you are painting, then you don’t need to worry about fat-over-lean because you do not have separate layers.
Even if you don’t paint in layers you may wish to control the amount of fat in your medium for drying times. Remember that any water that you have added to the paint, as water or in a WMO medium, will evaporate quickly and then the oil will start to dry just like conventional oil. Using a lean medium, more water, will result is faster drying because you have less oil in the mix.
One way to make your own WMO mediums is to take a WMO oil and add various amounts of water (which is our solvent, remember). A very lean medium would have 10 parts water to 1 part oil, for instance, and using neat oil would be the fattest medium you could make. All the proportions in between will make a scale of lean to fat mediums.
More Water Mixable Oil Painting Articles on the Blog
- Water-Mixable Oils: Vibrant Colours, Easy-Cleanup and They Needn’t be Sticky
- How to Start Painting with Cobra Water-mixable Oils
- Max Hale Reviews Cobra Water-Mixable Oil Colour
- Jackson’s Akoya – the Best Brushes Going for Oil, Water-mixable Oil or Acrylic
- Daniel Smith Water Soluble Oil Paint
- Cobra Water-mixable Oil Painting Mediums
- Make Your Favourite Oil Colour into a Water-mixable Oil Colour
- Water-mixable Oil Colour Drying Times
- Cobra Water Mixable Oils
- Trying Schmincke ‘Medium W’ for Oil Colour
References and to read more
Cobra have created an excellent series of eight videos on painting with water-mixable oils and using mediums.
Modern Paints Uncovered The article is The Performance and Properties of Artisan Water Mixable Oil Colour Compared with Other Oil-Based Paints by Winsor & Newton (pp 53-57).
Physical Properties of Traditional and Water-Miscible Oil Paints as Assessed By Single-Sided Nmr
Water sensitivity of modern oil paint films – Tate
Links to the materials at Jackson’s
Chelsea Classical Lavender Soap
Jackson’s Premium Cotton Canvas Art Boards
Postage on orders shipped standard to mainland UK addresses is free for orders of £45.
Wow a lot of effort went into this review. Great job!
Thanks Rob, hope you found it useful!
Nice article and very informative! My
students have just started learning
about Water Mixable Oils. May I
share bits and pieces of your article
with them to enhance their
knowledge? I would of course give
you full credit for the article, insight,
plus include the website. Please let
me know your thoughts. Thank you.
Hi Lisa
I’m glad you found it useful!
Yes, if credited, feel happy to share.
Can these mediums be used for water
soluble oil based printing inks?
Hi Susan
I have never heard of anyone doing it. Sounds like a great experiment! If you do try them it would be great if you could come back and let us know how it went.
can the water soluble oils be used with acrylic paints
in the same painting
Hi Anne
Although the WMOs are diluted with water, as soon as any water that you have used dries, then they act just like conventional oils by slowly absorbing oxygen from the air. They take 6 months or more to dry thoroughly and then must be varnished to prevent them from drying out too much.
So they are not really compatible because acrylic dries by evaporation and even a thick layer only takes a few weeks to cure. If the acrylic is on top it would create a barrier that would not allow oxygen to get to the oil. There would also be cracking issues because acrylic shrinks by 40% as the water leaves and oil swells as it absorbs oxygen.
So think of WMOs as conventional oils as far as making a mixed media painting. You can use them on acrylics so long as you are finished with the acrylics part and do not use acrylics again in the painting. No acrylics should go on top of any kind of oil paint.
I’ve started using wmo paints,
I didn’t realise they needed varnishing,
Which varnish do you recommend.
Hi Lynne
After the water has evaporated, which is very soon, then it should be treated as a regular oil painting. So any oil painting varnish or picture varnish is suitable. Wait the usual 3 to 6 months for the painting to be fully dry.
Very helpful. I have been considering a move to water-mixable paints and now I will give them a go. Thanks
Hi David
I’m glad you found it helpful!
After you have tried them, if you have the time, I’d love it if you’d come back and tell us how you got on.
Absolutely brilliant article. Thanks for such clear and in depth
research. I ‘m sure this will encourage a lot of people to make the
move. Thank you!
I’m glad you liked it!
I hope it will be helpful to many painters who are thinking about switching over.
Thank you for all your comments and
research, this has been very helpful. I
look forward to reading you’re helpful
articles.
Thanks, Dane
I’m glad you found it useful!
Thank you Julie for this informative
article. I note from your article that
Holbein Duo Aqua Painting medium
does not seem to work well with the
two types of water soluble oils that
you have tested (namely, Jackson’s
Aqua and Daniel Smith water mixable
oils). I wonder whether this has
anything to do with what the water
soluble oils are made of. Holbein
may have formulated their painting
oil mediums to work with their
specific modification of linseed oil.
This may also mean that Holbein Duo
Aqua mediums should only be used
with Holbein Duo Aqua oils, but not
with other brands of water mixable
oils. I am interested in your views on
this.
Have you tested the various types of
Holbein Duo Aqua mediums with
Holbein Duo Aqua oils? I would be
very interested in your findings.
Many thanks again for this useful
article.
Hi Betty
You may be right. I will test this hypothesis and get back to you.
Thanks for the suggestion.
Hi Betty
I tested the Holbein Painting Medium and Quick Drying Liquid and they both perform much better when used with the Holbein Duo Aqua paints. I will add this information to the article. Thanks for suggesting it.
‘Artisan – fairly strong chemical smell like
formaldehyde’
is it toxic to touch , or emanates toxic
fumes?
Hi Lara
I emailed Winsor & Newton about it.
This is their reply which says that there is something in the Fast Drying Medium which requires ventilation.
“Our artisan Water mixable fast drying medium, under CLP (classification, labelling and packaging of substances and mixtures) which governs consumer products in the European Union is classified for potential skin and eye irritation, safe use information is provided on the label.
Whereas our Artisan Water painting medium, do not carry health warning associated with it’s use.
The smell you have described is possibly the solvents in the products evaporating as they, we recommend using these products in a well ventilated room.”
I’ve just started using the WMO and so far
I really like working with it.. I’m a long
time watercolor artist, and wanted to work
with oils also. But I can’t have the smells
in a very small place.. I can’t thank you
enough for this truly in depth article. It’s
answered so many of my questions..
Thank you so much.
Hi Barbra
I’m very glad that you found it helpful!
Excellent information. Thank you for taking
the time to write such an extensive review –
much appreciated!
Hi Deb
Glad you liked it and found it useful!
Definitely worth reading. Thanks for taking
the time to test! I’ve discovered I get a bit
of a sinus headache when using the Duo
Aqua medium although not with the Duo
Aqua quick dry. As a result, I’m now
experimenting with the walnut oil with
pretty good success although I have to
remember to limit the amount I use to
maintain easy brush cleaning. I didn’t
realize I can mix other brands together. I
did know they were different
manufacturing processes so thought that
might not work. Thanks again!
Glad it was helpful Jon!
Fantastic, thorough testing and a lot of thought went into this article. Thanks very much Julie, it was most helpful!
I’m glad it was useful, Janice!
This site is very helpful. I’m using Cobra,
Lukas Berlin and Artisan WMO. Thank you!
I’m glad you found it useful, Agnes!
Good article. But why was artisan impasto
medium omitted? I have been using WMO
for over 6 months. Cobra (and Jackson’s
when I can get it). I use Cobra fast drying
medium which works well. I have found
Medium W to be excellent, as I can use it
to turn my existing oil paint into WMO.
Cleanup is a dream using the Marseille
soap. It is a pleasure to be free from
solvents. BTW, I have mixed water into the
paint to make washes for toning canvas,
and it has worked. My only problem was
that I bought Cobra painting paste. I
assumed it would speed up drying time
like the Artisan impasto medium. But it
does not. For this reason I think Artisan is
superior. Obviously, if I’m painting thick
layers of impasto paint, that will in itself
slow drying time. The paint can be over
5mm thick in places. It tends to form a
skin, with wet paint inside that has little
oxygen supply. So it takes forever to dry.
So, I cannot understand why an impasto
medium is not formulated to speed up
drying time. I was disappointed that the
Artisan medium was not featured here, as
it seems like the most suitable to my need
for texture plus fast drying.
Hello.
I had planned to do about half of the mediums just to give an idea of what they could do and about how they work with different brands of paint and about how the characteristics of each brand of paint are still very apparent because you use so little medium. I hadn’t planned to do every medium there was. But I added a few more to the list and ended up doing most of them. The Artisan Impasto wasn’t left off for a particular reason.
Thank you for sharing your experience of it, it sounds like a good product!
Very useful information . Can I ask about the use of Gamvar for
varnishing . They say you can safely varnish a painting when the
painting is properly dry to the touch and that there is no marking in
the fattest areas of the painting when you press it with your nail . If
a painting is especially lean in technique is it safe to varnish a
painting with gamvar when it is dry to touch ? Thank you
Hi Janette
Because Gamvar is a modern synthetic varnish designed to allow the oxidation process to take place through a permeable varnish layer, you can apply it to a touch-dry oil painting. Be wary of some areas still being wet though, that you may not have noticed. You could begin to varnish the painting only to discover that a couple of small spots of white were still wet and smear them across the painting. So double check your slow drying pigments like titanium white, crimson and ivory black, to make sure the whole painting is touch-dry.
I double-checked and Gamblin say if a painting has been made with thin layers and fast drying mediums, it could be ready to varnish with Gamvar in as little as 3 weeks.
I have just discovered this site and I who
uses water soluble oil paints is very
impressed with your technical information.
Thanks for your great work.
Welcome to the Jackson’s Art Blog!
I’m glad you found the article useful!
Hey, thank you for this article, I repeatedly
referenced this for my extensive research
in potentially buying WMOs.
I do have a question, if I convert regular
traditional oils with Schmincke’s Medium,
can I use those converted oils with WMO
mediums from Daniel Smith or Winsor &
Newton?
For example, If I use Medium W with the
Mussini oils, can I use those converted
Mussini oils with mediums designated for
WMOs?
I ask because some of the traditional oils
brands have specific pigments that I would
love to use (namely PB16 Phthalo
Turquoise), and the WMO brands I
researched don’t have that specific
pigment. I would love to use PB16 and
PR255 Vermillion Hue in oils, so I figured
I’d ask the question above. I hope I’m not
bothering, thank you!
Hello
I’m glad you found the article so helpful!
I asked the technical team at Schmincke and this is what they told me:
The Medium W makes the colour leaner, so begin with a very lean mix of colour with much medium and water and then increase the oil-colour-content in the mix with every layer to follow the fat-over-lean-rule.
There should be no danger in using different brands together but since we didn’t test all mediums, we cannot guarantee that it will 100% turn out as you like.
Please do pre-testing with any new materials, tools and techniques before using it in your artwork.
Can I used isopropyl alcohol as a medium
with oil soluble paint? Can I use it to clean
brushes?
Hi Rita
No, isopropyl alcohol will cause oil paint to seize up and make a gooey mess.
Hi, I was wondering did the Holbein Painting
Medium act the most like turpentine?
Hi Mark
Although it had the thinnest consistency and spread very far on the palette it did not act like turpentine when mixed with the paint. When mixed with most brands of paint it was a bit sticky, though later trials mixing it with Holbein Duo Aqua, it was smoother.
If you would like to thin water-mixable oil to the consistency of a turpentine wash that you would get with conventional oils, then the solvent to use would be water. Some of the brands of water-mixable oil paints thicken with a small amount of water but they all melt into a thin wash when you add a lot of water.
Thank you for this article. I have used m-
graham walnut-alkyd-oil-medium for a
couple of years for quicker drying in normal
oil paints. I initially used this as I wanted to
be as close to a toxic/‘chemical’ free studio.
But I find this medium a bit to glossy and
sticky for initial under painting. I have
recently tried a orange oil thinner which isn’t
sticky but creates a film which isn’t always
practical, painting over this film sometimes
makes the new layer have a orange peel
effect. So I started using water mixable oil
paints by Windsor Newton with water for
under painting. With a limited pallets at
present I am happy with this but haven’t
tried using fat layers yet. Your article was
very useful, I didn’t realise it was possible to
add the walnut oil to these paintings. I
definitely want to use more water mixable
oils, probably one of the two brands you
mentioned.
Which medium to you consider the best for
quick drying under painting where I can
avoid the sticky gloss issue?
It seems like the Jackson paints would be a
better option for this?
Hi Charlene
Yes, it sounds like you might want to try a tube of the Jackson’s Aqua Oils to see if they will work for you. I think they are the most likely to give the slightly matt finish you are looking for. It would be great if you could come back and let us know how you liked them, it would be good to know if they are particularly suited for underpainting.
thank you, I will try them and let you know
I use acrylic on oils and have no issues.
Doing it since the 80’s. see my work on
facebook. John Killmaster.
Most people find there are adhesion problems, that the paint can scratch off in places. Materials experts and conservators warn against it if you want a permanent painting. But the art comes first, so if that is the way you make your work, that is of course, fine.
I used Artisan water soluble oils for my latest painting. I did not use any medium other than water. Once the painting is dry all over can I use a fast drying medium for the final layer of paint. This painting was an expensive commissioned painting but has been endlessly frustrating because of the slow drying of the paint layers. Thank you. Enjoyed your article.
Hi Joe
Thanks, I’m glad you found it interesting!
It is never recommended to apply a fast-drying layer over a slow-drying one, it’s the opposite of the fat-over-lean principle and is not a sound structure.
Has the drying time been unusually slow, how long is it taking? Is it actually wet or just tacky? Artisan is one of the brands that stays tacky even after it is dry and I have found you need to apply varnish to harden it off.
Can you tell me whether WN Artisan Thinner
would work with Cobra WMOs? I found the
WN Mediums get too gloopy with the Cobra
but would prefer not to rely on water alone
for underpainting or thin layers as it dries to
a very flat finish
All the mediums intermixed with the others. But if you found the consistency of the other Artisan mediums didn’t work well, then maybe you wouldn’t like the Thinner results, either. Maybe give it a try to see what you think.
Thank you so much for this in-depth
article! I’ve just ventured into water-
soluble oils and am reading as much as I
can about them. Would you please explain
to me the difference between the Daniel
Smith Painting Medium and Modified
Linseed Oil? They seem to have the same
effects, but I must be missing something.
Hi Elisa
I wrote and asked Daniel Smith to clarify. I hope this is helpful.
Daniel Smith:
“Generally speaking, the binder(s) used in our WS Oil Mediums are listed on the labels.
DS WS Painting Medium contains Safflower Oil and Alkyd Resin. When mixed with DS WS Oil Colors it will keep the drying time the same, and is used to thin your WS Oil Color.
DS WS Fast Drying Painting Medium contains Linseed Oil and Alkyd Resin. When mixed with DS WS Oil Colors it will speed up the drying time by 1-2 days.
DS WS Fast Drying Linseed Oil contains Linseed Oil. When mixed with DS WS Oil Colors it will speed up the drying time by 1-2 days.
DS WS Modified Linseed Oil contains Linseed Oil(listed as Oxidizing Oil on the label). When mixed with DS WS Oil Colors it will speed up the drying time slightly, 0-1 days.
DS WS Safflower Oil contains Safflower Oil. When mixed with DS WS Oil Colors it will slow the drying time by 0-1 day, and is used to thin your WS Oil Color.”
Hello Julie
I’m using water mixable oils for the first time. I used safflower oil
with the paint for the first colour layer. I think I used to much oil
because it definitely needs another layer. Should I use even more
oil or can I just use paint only or paint with just a little oil mixed in?
The painting is dry to the touch, it was done about a month ago
I’m not sure what you mean – why would using too much oil mean it needs another layer? It’s too shiny? Is it taking too long to dry and you think this means it needs another layer? Is it sticky?
The fat-over-lean principle is used by oil painters for two reasons: 1. it makes a more stable surface with less potential for cracking and peeling years later and 2. it it hard for a layer of paint to stick to a previous dried layer of paint if it is very oily, so you don’t want to get very oily until the end. This adhesion problem can mean that you can easily scratch the second layer of paint off after it has dried because the dried oily surface underneath is very ‘closed’, without pores to grab onto so the upper paint isn’t adhered. Safflower is even worse than linseed for this.
In your case, if you have used too much oil in the first layer and you want to continue on with the painting rather than chalking it up to a learning experience, I would use the same amount of oil and not increase it more. If it is because it is remaining sticky even after it has dried, that is the characteristic of many water-mixable oils, and the solution is to varnish the painting which makes the surface hard and not sticky.
Hello Julie,
I’m using Winsor & Newton Artisan
WMOs, and a small, dull, matte area has
appeared (“sunk in”) within a glossy,
tacky section of a painting. I started
lean and gradually added less linseed oil
to French Ultramarine. Is this fixable or
something to chalk up as a learning
experience? (I tried, unsuccessfully,
wiping the dull area using a cloth and
hot water. Oddly that worked on a
previous painting (Pthalo Blue), but the
French Ultramarine seems to have dried
enough fairly quickly).
Kind regards,
Andy
Hi Andrew
A sunk in area is an area of low oil content.
You say you added gradually less oil, do you mean you added gradually more oil?
If it was adding less oil that might be the problem.
But if you added more then I don’t know why it happened. Is there an umber colour underneath the blue? That can suck oil from the layer above.
There are two possibilities for fixing it.
Add a drop of oil on top and wipe it off almost completely. This oiling out means the area will yellow more in time and your blue could go greenish. It will also take some time to dry. But when it is touch dry you can paint over it with blue again to cover the yellowness and restore the area.
The second option is to varnish. Varnishing makes the whole painting the same amount of gloss or satin or matt. And it gives a hard, smooth dry finish to any dry but tacky areas.
Thank you very much for the time and
effort . I learned alot .
I have a question please.
Can i mix Artisan Water Mixable Thinner
Medium and Graham Walnut Alkyd Oil
Medium ?
Thanks in advance
Not to pre-mix together in a bottle, but to mix some of each with some paint, right?
I haven’t tried it but it should be fine.
Remember that the Graham can’t be used more than a drop per cm of paint or it won’t dry. So be sparse with it.
Hi Julie!
Thank you for all the information!
Is it possible to make the Artisan Fast Drying Medium thinner and still keep its fast drying property? …maybe with the Thinner or the Painting Medium?
Also: is it possible to use alkyd mediums or Liquin with WMO to speed up drying time?
Thank you!
Hi Maja
You can mix the mediums, but you will need to try different combinations to get the speed of drying and flow that you are looking for.
Yes, you can use conventional oil mediums with WMO but at a certain amount they stop being water-washable.
The most popular medium used with WMOs is not a WM medium – the M Graham Alkyd. It gives loads of flow using just a few drops and speeds drying.
If the WN thinner is less like turpentine and
more like an oily medium, would this mean
I’d have to add medium in the next layer?
Hi Phil
Good question.
It feels and acts like a medium, so I would assume it is at least somewhat fat. Not lean like what you’d expect from something called a thinner. It is superb for adding flow, which is sometimes called ‘thinning’, because the word is used for two different meanings. Thinner usually means to reduce fat, make more lean. So it usually refers to solvents. But it can also mean to reduce thickness and make more fluid, which can be done with an oil. But I refer to that as increasing flow, rather than thinning, to avoid this very confusion.
I have emailed Winsor & Newton to ask where it falls on the fat-lean scale. And will get back to you.
Hi again Phil
I have heard back and Winsor & Newton say it should be considered lean. So in a fat-over-lean situation it is not adding fat, it is thinning and adding flow.