The best medium for plein aire painting- oil? - WetCanvas: Online Living for Artists (2024)

MS_Triple

Oil Paint:
Pro- Oils have that buttery quality and enough open time for blending color on the surface so vital to spontaneous and time constrained conditions typical in plein aire.
Con- Oils are messy to cart around and prone to collecting fragments from the terrain.

I will not compromise the archival integrity of the paint by using a dryer when painting with oils.

Acrylic Paint:
Con- Acrylics dry too fast thus require more premixing due to less open time for spontaneous natural blending on surface.
Pro- They dry fast so you can paint on unstretched pieces of canvas that roll up so nicely.

Mainly because of the fumes (indoors) I have been experimenting with acrylic paint. Fortunately there are quality manufacturers that do their best to mimic oil paint. My first experience was with Liquitex brand -a poor representation of acrylic paint as it is gooey and foams easily. Other brands have the buttery behavior minus the greasy character of oil. This greasy aspect is partially responsible for the wonderful blending quality of oil paint and is missed to a degree. Depending on your technique, style and preferences painting with quality acrylic paint can be a rich experience similar to oil in many ways.

I wish the open time was longer though. The retarders and flow release mediums do not widen the window sufficiently to allow the natural blending critical in plein aire painting. The outdoor elements shorten this open time and in compensation the various mediums only weaken the paint integrity.

Alkyds can’t be that great or you would have seen more than 2 brands world wide during the last 30 years. They are noticeably wax-like and transparent in consistency. Oddly they feel less like oils than acrylics.

I have left out many pros and cons and other mediums like watercolors and pastels.

What is the best medium for painting in plein aire?

May 3, 2003 at 9:33 am#1009746

Larry Seiler

some of the freshest paintings as though done yesterday are the works of the Impressionists.

Part of that movement of the Impressionists were also the many American masters whom traveled to Europe to learn and were contemporaries of the Impressionists working with and knowing them personally.

A good number of these painters then came back and set up schools such as the New York Student Art League, the Cape Cod school, and eventually influencing the Buck County PA painters.

While the Impressionists of France perhaps use little medium or dryers that we know of….we do know that American Impressionists (from the writings of Charles Hawthorne and John Carlson) used “oil of copal”….and some went so far as to varnish their paintings as soon as the paint was dry to touch.

Little is said about this practice or considered on boards around here, though I stir the pot up a bit by every so often mentioning that.

the copal found in typical art stores is priced to sell and made improperly. It is not REAL copal.

On the other hand…the real McCoy (as they say) is an excellent oil medium causing the paint to have a buttery consistency. A maker of such sent me some complimentary copal to try about six years ago….and I’ve been painting with it since. The immediate handling of the paint was as though the paint painted itself. It was like the difference from driving a Yugo….or an expensive luxury vehicle.

The paint had an immediate jewel-like quality that matched the intensity of color I was seeing outdoors, sat and held precisely the way I applied the paint. It made my alla prima methods seem a snap!

The other two qualities of true copal is that it is also a natural varnish…and if you mix it properly with your paint, you control the degree of final sheen. Though, for restorer’s purposes I usually apply a damar varnish. Thus, if the damar is removed, being a different varnish from the copal…the attempts to remove it would not affect the paint.

Yet…if perchance I had a spontaneous buy (and we know they rarely if ever come back to buy down the road), I know I can let the painting go because technically the painting itself will dry strong and be protected.

Lastly, true copal is a natural siccative. It does not dry as a film on the surface outside and eventually in, but attaches itself molecularly to the pigment drying uniformly throughout. This is why the old American Impressionists had no qualms about immediately varnishing when dry to touch.

Personally…even though they did that…I like to wait a month to three months. Just old fears that won’t die I guess…..

I painted an 18″ x 24” plein air last saturday using true copal as my medium, and it was nearly all dry to touch Monday afternoon already.

Now…as to you question on preference….there is no “best” medium arguably for all artists.

Mediums are like conduits that allow for what is in you to naturally come out. If watercolor allows that free flow of creativity and response to nature happen, then that is the best. Sargent’s many many masterful watercolors of landscapes are themselves a testament to that!

I paint in all mediums, and acrylics are great as well. I tend to add extender gel medium to acrylics which gives them more body when dry that holds texture. In fact, some of my acrylics have been labelled wrong at galleries….thought to be oils. I have had to correct a few galleries to that error a number of times.

My preference though is oils.

I like the mess. The smells.

I like the routine. The nature of oil to sit and hold to a thick impasto that mixes in the viewer’s eye from a few paces back. The three dimensional nature of oil itself by sitting up off the surface to capture light and hold light within itself adding to the power of a color to transfer a sense of intensity in chroma.

Then…I also like pastel, and I lay down a watercolor wash, and then build pastel on top. There is an immediacy that I like about that as well….

oh…my source for the real McCoy copal is Garrett’s copal-
http://www.garrettcopal.com

also, Studio Products carries a good copal…

Larry

Larry Seiler- Signature Member IPAP; Signature Member American Impressionist Society AIS
Main website! https://larryseiler-artist.com/

May 3, 2003 at 9:37 am#1009754

TedB

I use no mediums for plein air works.

I suggest no mediums for plein air work, for that matter for any work, unless one has fully studied the research.

I know of a panel made about ten years ago using most of the available mediums at that time including Maroger, black oil, stand oil, raw linseed, damar, copal concentrate, Venice turpentine etc. ALL of them yellowed and darkened. The alkyd (Liquin) has yellowed no more nor less than any of the others. The stand oil — supposedly less yellowing — has darkened noticibly.

About a year ago half of the swatches on this panel were covered with an opaque cardboard and exposed to the summer sun for three days. ALL restored close to their original light color. Conclusion: all mediums yellow and darken, but sun bleaching can restore………. ???

May 3, 2003 at 9:47 am#1009747

Larry Seiler

of course its everyone’s preference…but Carlson spoke of a process which artists did in his day I believe he called, “seasoning”….

works that dried, perhaps even darkening…were set out in the sunlight for a period of time…a day maybe, (I’ll have to go back and look) and the sunlight affected some chemical property (again that he called seasoning)….and the result according to his writings is that the painting would never thereafter yellow.

I don’t know any better way personally than to invest in the books I have of yesteryear, see what they did….and see the results of their works in museums today. I am of course not trying to be a smart aleck…but if other ways of knowing are more conclusive I’m always interested.

I did belong to a listserv group once, and it evolved around Don Jusko’s site….where he has about 300 pages online of studies and histories on varnishes, paints, mediums, methods and techniques and Don himself has done a lot of personal studies on yellowing….still, I haven’t heard much discussion on the techniques of those we call the masters whom themselves understood this potential problem evidently.

I will try to learn more about seasoning…and try to be better prepared in the future to make a more educated treatise on that technique..

I have tried using oils with no medium, but I just don’t like the pastiness, the drag….just not for me. Pass me da butter…

interesting thread….

Larry

Larry Seiler- Signature Member IPAP; Signature Member American Impressionist Society AIS
Main website! https://larryseiler-artist.com/

May 3, 2003 at 9:58 am#1009755

TedB

[i]Originally posted by LarrySeiler [/i]
[B]
I have tried using oils with no medium, but I just don’t like the pastiness, the drag….just not for me. Pass me da butter…
Larry [/B]

Understood !

Just a THOUGHT ! perhaps with different brands of paint one can identify those which DRAG and those which DO NOT DRAG ! LOL ! I experienced THE DRAG when using WN oil paint….but, have found NO DRAG or PASTINESS with the handmade pigments from Robert Doak and/or Williamsburg. Sometimes I have TOO MUCH butta !

May 3, 2003 at 10:20 am#1009748

Larry Seiler

but then again…technically then Ted…aren’t the agents added to the oils in the grinding process in and of themselves types of mediums?

Safflower oil, linseeds….etc;

IF you find a paint with a good drag…technically it would just have more oil of some kind added to the mix correct? So then, knowing what oil that is…one in theory should be able to add like oil to get an otherwise difficult think paint to cooperate. Or, so I would think….

Still…there is a chance then that THAT oil might as a character of that oil in time yellow…and seasoning might yet be an answer.

This is what I love about painting, and playing music. You can do this your whole life…teaching others, yet turn around and find yourself the student. Living shows life to be rich!

Larry

Larry Seiler- Signature Member IPAP; Signature Member American Impressionist Society AIS
Main website! https://larryseiler-artist.com/

May 3, 2003 at 11:28 am#1009756

TedB

[i]Originally posted by LarrySeiler [/i]
[B]aren’t the agents added to the oils in the grinding process in and of themselves types of mediums?
Safflower oil, linseeds….etc;
IF you find a paint with a good drag…technically it would just have more oil of some kind added to the mix correct? So then, knowing what oil that is…one in theory should be able to add like oil to get an otherwise difficult think paint to cooperate. Or, so I would think….
Still…there is a chance then that THAT oil might as a character of that oil in time yellow…and seasoning might yet be an answer.
Larry [/B]

Oh sure……i know i agree. i often think i prefer the pigments not processed with LINSEED OILS…..walnut oil and poppy oil work nicely. For me, that is !

BTW, Carlson used half-and-half mixture of turps and oil of copal varnish. He specified NOT picture copal varnish. His belief was that such a mixture LOCKED and PRESERVED the life of the color.

About seasoning: I am coming to believe that for work in oils, one does best to use a substrate prepared with oil gesso rather than a commonly used acrylic gesso, and allowed to season for maybe 6 months before painting. No final words yet !

May 3, 2003 at 12:30 pm#1009753

DFGray

Pastel…medium of the gods

May 3, 2003 at 2:30 pm#1009749

Larry Seiler

[i]Originally posted by TedB [/i]
[B]

Oh sure……i know i agree. i often think i prefer the pigments not processed with LINSEED OILS…..walnut oil and poppy oil work nicely. For me, that is !

BTW, Carlson used half-and-half mixture of turps and oil of copal varnish. He specified NOT picture copal varnish. His belief was that such a mixture LOCKED and PRESERVED the life of the color.
[/B]

I’ve heard some good things about walnut oil too….not familiar with poppy…

and I would agree with Carlson at least in how I work. Though I do not mix my copal with turps, the solution Garrett makes has a formulation of turps in the copal, with exception of his concentrate. But…I refrain from using the copal myself as a final varnishing.

my work is not time tested so I can’t say “locked”…but as for preserving the life of color I am very satisfied with the results the copal has had on my color.

To me….attempting to translate to paint what my eyes see on location has required a particular look and feel to the pigment, that intensity which is demanded of by that dadblasted taskmaster we call the sun.

peace,

Larry

Larry Seiler- Signature Member IPAP; Signature Member American Impressionist Society AIS
Main website! https://larryseiler-artist.com/

May 3, 2003 at 3:14 pm#1009757

TedB

this i borrowed from Sinopia.com…….thinking it might help others with questions.

Making Oil Painting Mediums

The most important thing to understand about painting mediums, are the characteristics, that each component of a medium possesses, so that the artist can create a desired paint film. For example, if one wanted to create a glossy surface, one would use a Dammar varnish. Dammar, though a fine varnish on its own, is too viscous in its manufactured state and therefore needs to be thinned with turpentine. Dammar also dries into a very brittle film and therefore should be made more flexible by the addition of an oil. This is only an example of how to ascertain a desired finish and knowing how to compensate for its shortcomings. In order to help ascertain other qualities for a desired paint film, here is a list of available oils, varnishes and driers and their characteristics.

Oils

Linseed Oil
A drying oil that dries to a semi-gloss to matte finish, depending on the pigment it contains. It dries relatively slow.
Walnut Oil
Also a drying oil that dries to semi-gloss to matte finish as well. It is usually used in oil-egg tempera emulsions.
Poppy Oil
A very slow drying oil, that is very clear and dries to a brittle film and therefore recommended to be used in combination with a more flexible oil such as linseed oil.
Sunflower Oil
A non-drying oil that is very clear.
Lavender Oil
A slow drying oil, which retards the drying time of other oils.
Clove Oil
Also a very slow drying oil, which can be added to other oils to retard their drying time. Use only drops.
Balsam

Larch, Venetian and Strasbourg Turpentines
Very viscous turpentines, which are left in their post extraction state or made more viscous by the addition of colophony resins. They make a beautiful thickener for oil painting mediums. Especially suited for mediums that are used in fine detail or glazing work. They must be used in combination with an oil to prevent cracking.
Canada & Copaiva Balsam
Also gained by extraction from trees, that contain a mixture of resins and oils. These two are hailed as the best because of their workability and the ability to use them as a sole medium.
Rectified Turpentine
The product of the distillation of the viscous pine tree sap. In the distillation process such resins as colophony are removed to create a clear liquid which makes a great thinner and drier for all oil painting mediums. Turpentine has no binding power on its own and can therefore not be used alone in combination with pigment.
Varnishes

Dammar Varnish
A combination of rectified turpentine and the crystalline Dammar Resin. As mentioned earlier it creates a glossy film that needs to be stabilized with an oil and can be thinned with turpentine for easier brushability. By the addition of beeswax the glossiness of the film can be reduced from a semi-gloss all the way to matte finish.
Mastic Varnish
Manufactured in a similar fashion as Dammar Varnish. It also dries to a glossy finish, but remains more flexible in film than the Dammar and is therefore preferred as a picture varnish.
Driers

Cobalt Drier
A very potent drier that should be used in very small (drops) quantities. Too much drier causes paint films to crack.
Turpentine
Also acts as drier and can be added generously as drier to oil paints.
All of the above ingredients can be intermixed to create any sort of paint medium (slow drying, glossy, matte, viscous, etc.). However, it is important to consider whether the painting medium will dry in a reasonable amount of time and whether the dry paint film will be flexible enough to keep from cracking.

May 3, 2003 at 3:57 pm#1009758

way

i agree with tedb, no medium.

it just doesn’t make sense for an alla prima painting.

the use of mediums should be used with caution as they all break down the chemistry of the paint. even trups.

in a classic sense mediums have only really been used to facilitate certain styles of painting, such as glazeing where a thinner paint film was desired for that “inner glow”, or stand oil or venice turps to make highlights stand-up on the surface such as rembrandt, but even his paintings are still oozing up from below the crusty surface, not good, or slowly sliding down the canvas…yikes. i have had this happen to me by using too “fat” a mix of stand oil. it felt good at the time, but the whole painting just kinda sagged after a few weeks.

the only other reason i see the need of a medium is when the dark values in a work lose their saturation and appear lighter which then can skew the balance of values. then you need to add a medium to regain those darks. but this only really applies if you are working on a piece over several settings and need to be able to judge the values as you paint. then you can use a medium (oil) thinned with turps to “pull back” those darks. i do this sometimes by rubbing mix of turp and oil into the area before painting.
and if you need a “longer” paint for details (i don’t personally) and thin with turps only then you have broken down the oil binder, this must be relpaced during the painting process or after.

so ….this just doesn’t apply to alla prima painting where the color is applied, most likely, straight from the tube.

another thing to consider; working light colors with the knife will bring the oil to the surace where it will yellow faster. so use a white or lighter colors that are made with better oils such as safforn or poppy to reduce the chance of this happening. better paints makers always use diff (better) oils as a binder in lighter colors then the darks which use linseed, where yellowing is less of a problem.

hope i stated this without stepping on any toes. but the bottom line is any medium used other then the paint will cause problems in the future, even turps. almost always.

another tip. if you would like a “short” paint consistancy, use a peice of cardboard as a palette and allow it to soak some of the oil out. then after the painting has set for a bit (dry to the touch, but not hard) replinish the oil that holds the paint together by rubbing it into the surface. i personally would avoid this in light areas though, for the yellowing reasons. i would just let those areas stand as they are.

and i don’t, as a rule, apply a final varnish on any of my work…i have just not seen where that is a good idea. it is far better as to reguards of restoring, to clean the paint surface with a mix of turps and a rag then to have to remove yellowed varnish with a brush. the only good reasons i have seen where this is necessary is where a medium was used in the darks to retain the saturation and now has a different sheen then the lighter passages. then, if that concerns the artist a varnish of some sort is required. but damar is really brittle, but widely excepted. tough choice

also, the paints we use today, from the big manufacturers anyway, have all kinds of stableizers included in the mix to keep the oil and pigment from separting in the tube, so there is some junk in there to beware of. i used to use blockx paints almost exclusively and was a little concerned that the oil and pigment in some colors would always separate, untill i learned that better paints mixtures are designed that way. they are just more pure and you just mix it back together on the palette. i don’t think we recognize up untill the impressionist paints were really runny (sp?) and kept in sacks, or bladders instead of tubes. check out turners work, his field paint box was made up of colors in bladders with a stoppers.

laterz

May 3, 2003 at 7:13 pm#1009762

MS_Triple

I agree there is not necessarily a “best” for everyone and it is encouraged to experiment and explore and alternate mediums – ideally keeping each spoke relatively symmetrical so the wheel rolls smoothly. Under the conditions of plein aire, however, there are mediums better suited in addition to personal preferences. You probably would not find too many artists welding, sculpting or airbrushing in plein aire

I also “love” the smell of oil paint. I associate it with one of the top experiences in life. Specifically, the fumes have separate consequences from the scent. I do not have a large studio space with ventilation.

I have tried pastels in the field. I wanted to take advantage of the array of color in a more controlled medium -“controlled” at least there usually is not liquid involved. Everything is relative. I have always considered pastel to be very loose yet I have mistaken pastel paintings for brushed paintings so it is possible to control it to any degree. I am partial to brushed painting though.

As for the buttery quality of oil paint, doesn’t the pigment have some influence over the type of oil? Some pigments dissolve, others blend and others need to bind with the oil long enough to be used effectively as a paint. The character of the pigment also has something to do with the amount of oil mixed in a tube paint. Some colors tend to be thicker, dryer, and perhaps grainier in a subtle way than others. There are runny paints at both ends of the spectrum -cheap to finest. Many manufacturers work at maintaining a line of paints with consistent viscosity. Examining the finest lines illustrates the true inconsistencies attributed to pigment and oil character. When using the finest paints the artist has some room to add a drop or dip the brush in certain mediums if it is the same material mixed in the tube of paint. (Granted we understand the finest lines have the least foreign additives and are typically inconsistent from color to color).

Forgive me if it seems like point-counterpoint. I don’t wish to offend or defend. There is limited space and I only wish to interact on the topics -not intending to step on any toes

May 4, 2003 at 3:25 am#1009750

Larry Seiler

I don’t think any toes are being stepped upon. That is for people who are overconcerned with how others perceive them, and then get all worked up because someone challenging them threatens to make them not look good.

I can appreciate painters not using any medium. That’s precisely the way a number of Impressionists work.

I tend to follow the princples of physics in its most basic form. “It works, because it works!”

For me…my work has been quite satisfying over the past half-dozen years both just in painting and how others have responded to them and I attribute part of that to my use of copals.

I don’t think I’ll stop using copal because others feel strongly against its use, and certainly I don’t expect others will begin using it because I endorse it. Its a question of liking the paint. I like the paint with the copal in it. I don’t like it inconsistent, and particular colors with no medium are thicker, or heavier. Instead, I like to get them to consistency.

I do appreciate hearing and seeing how others work, and of course there is always the chance of doing something a bit different…or seeing fine examples. Settling into what it is that we do is what will make our work unique, different, diverse…..!!!!

peace,

Larry

Larry Seiler- Signature Member IPAP; Signature Member American Impressionist Society AIS
Main website! https://larryseiler-artist.com/

May 4, 2003 at 3:55 am#1009759

way

good points ms_triple and larry seiler,

my only point that i intened to make is that when one uses any medium, including turps to thin, it is breaking down the binders in the paints. so if turp is used to thin a paint, then oil must be added back at some point to bind the pigments back together. so it would stand to reason then that the safest way to paint by far is alla prima with no added mediums.

i used to make my own pastels and can attest to the fact that different pigments act different with a given binder, some are so light that is becomes very difficult to even get them wet. while others are glassy and hard which can make a pastel scratchy on the surface, so additional things like talc or in my case oatmeal “juice” is added to soften the pastel stick.

so it would be with paints as well. in boutique oils like blockx one can clearly see how some pigments bind and others float in the medium. then in the WN line all the paints have a similer consistancy which is arrived at by varying the binders or adding fillers to round the the body.

i think it has been born out in the history of using oil that alla prima paintings have faired the best through time. except the impressionist work where also little if any medium other then the binder in the pigments was used. and these guys worked thier canvases over for months on end.

for my self, since i work on the same painting over an extended time adhesion between layers is of great concern, so i am very careful with adding to much of anything to an already fugitive balance of chemistry.

also oil really hasn’t been around that long compared to encaustic or egg tempra, so we really are not sure how oils will hold up. what we do know is that they are very complex in drying and there are plenty of good examples that show us that oils are a fugitive media at best. they will yellow, they will dry unevenly between layers of applied paint, they will crack and seep wet oil hundreds of years after the surface is dry.

so….
use mediums with care and balance for sure, or just do it all at one time. like most of you are doing already, it is the safest route.

May 4, 2003 at 12:56 pm#1009751

Larry Seiler

a good affirmation Way….

With the Canadian weather fronts and Great Lake affects we get here in the northern Midwest of Wisconsin and upper Michigan, no two days are rarely alike. In fact, hardly is one hour like another. As such, since I often hike good distances into remote places…I never go planning that returning again to finish is an option. So, my methods are always alla prima.

So, hopefully as you point out well about the longevity of alla prima painting…perhaps my limited use of copal as a vehicle will balance out.

My challenge before me is the accomplishments of Edward Redfield, (Buck County) …which is becoming a sort of legacy for me to ponder. Completing 50″ x 54″ canvases on location alla prima ie., in one day routinely. Wow….!!!

As for archival…we know from environmental studies that plastics left to lay in the environment are detrimental for the reason that they have a 125,000 year half life.

If the polymer plastic like nature of acrylics in their dried state is any similarity…the paints ability to stretch with the support probably is likely to far surpass the longevity of most paints. I am equally comfortable painting acrylics, using a gel for body and impasto like application effects. I just like the jewel-like intensity of oil color outdoors, and those wonderful smells.

well…appreciated your last post here Way…thanks,

Larry

Larry Seiler- Signature Member IPAP; Signature Member American Impressionist Society AIS
Main website! https://larryseiler-artist.com/