There are many possible mixtures of resins, drying oils, essential oils,
petroleum distillates, and alcohols to produce a painting medium. The most
widely accepted in today's training is a mix of Stand Oil (linseed),
Damar Varnish, and Rectified Spirit of Gum Turpentine. I have, since
the late 1980s, used a mix of Stand Oil and Damar mixed 1:1 and diluted
by progressive measured degrees (6, 4, 2, 0 ) with Triple Rectified Turpentine
in order to produce an increasingly fat film as I add layers. This mix
is, however, the maximum that can be allowed, as Damar is resoluble in
turpentine.
*Words of Caution*
Ralph Mayer has written in his book The Painter's Craft: "History
teaches us that the wisest course is to adhere to the simple oil-paint
technique as much as possible, to use oleoresinous painting mediums with
restraint and to avoid complex jelly mediums" like megilp or Maroger's
medium.
AVAILABLE PRE-MIXED MEDIUMS
A pre-prepared medium made of the above ingredients is sold by Daniel
Smith in pints and quarts that can be further diluted with turpentine
as needed.
There are many other generic mediums that do not list their ingredients,
only their effects, that are listed as Artists', Fat, Smooth, Lean, Colorless,
Classic, etc. medium. But the following mediums of at least partially known
ingredients are on the market.
Creative Mark produces a copal resin painting medium.
Flemish Siccative by Lefranc & Bourgeois is a copal resin based
quick drying medium which yields a paint film with an enameled-like appearance.
I have also been contacted by Ron Garrett concerning the copal medium he
produces and sells at http://www.garrettcopal.com
Holbein's Lesolvent De Colore - "an ideal mixture of Turpentine,
poppy Oil, Siccatif and resin. this ready to use painting medium will speed
drying time and add vivid lustre and smoothness to your painting applications."
Oil of Spike Lavender - "used as a medium to give body to
the color as well as a certain amount of bite, which improves adhesion
to the lower layers." --Lefranc and Bourgeois
I have been told that it can have the effect of either increasing or decreasing
dry time, depending upon that with which it is mixed.
Duroziez Harlem Siccative Medium - "speeds the drying of
oil colors and brightens the hues of colors." Lefranc and Bourgeois
Apparently a form of drying medium used by academic painters of the late
19th century invented by a Mr. Durozier of France. Critics say that the
original siccatif de Haarlem and siccatif de Courtrai both contain ingredients
that turn dark, brittle and crack. Cobalt drier is recommended as the least
harmful drier to add to paint films; little is needed. (alkyd mediums may
be a safer modern additive)
Flemish Medium - "This gel medium made with gum mastic is
used to recreate the effects put into practice by the Flemish masters.
Perfect for brilliant and precise detail work. Finished paintings have
a luminescent, glossy appearance." --Lefranc and Bourgeois
This is most likely a form of Megilp, or mastic melted into boiled linseed
oil and litharge or lead dryer. Similar to Sennelier's Maroger Medium
- "believed to be the lost secret ingredient of masters such as Titan,
Rubens, Rembrandt, and Vermeer. First re-created by Jacques Maroger the
head curator of the Louvre in the 1930's. Made by combining oxidized linseed
oil and mastic varnish resin to create a gel-paste. When mixed into colors
they become richer and deeper and remains lustrous even when dry."
An emotional debate rages as to whether or not the use of a boiled oil
is archival in painting mediums. Many claim that the lead dryer never ceases
to oxidize the paint film, endangering its permanence and long-term flexibility.
It is said that "the notorious megilp of the late 18th and 19th centuries,
popular for the ease with which it imparted a 'Dutch Master' look to the
paint, was early associated with severe cracking when the pictures were
varnished. Though it is possible that the Maroger medium is not identical
with megilp, it does consist of the same ingredients...."
Venetian Medium - "Made of mastic and wax this medium
will give the paint film a satin sheen. It will facilitate impasto work
and superimpositions while regulating the drying process." Lefranc
and Bourgeois
Dorland's Wax Medium - "when mixed into oil colors this
non-yellowing wax and resin mixture actually strengthens the paint
film against shrinkage and cracking and seals out dirt, air and moisture.
Dorland's improves luminosity and clarity of all colors with no chance
of muddiness of tone. The choice of professionals worldwide. Mix directly
with color."
Wax mediums have their history in encaustic painting. One should investigate
thoroughly their stability in an oil painting, especially if painting in
layers. This artist has never used them.
"Blockx Amber Mediums: The Secret of the Great Masters -
"Are you missing the lost ingredient in your paintings? If you would
like the colors of your paintings to be as brilliant in 100 years as they
are today, the paint film to resist virtually any damage due to atmospheric
pollutants and your paintings to take on a 3 dimensional quality, then
the answer is yes! Made famous at the old Flemish school dissolved yellow
amber has allowed great works of art to stand the test of time and impart
a rare luminosity. amber is the finest of all resins. Just a few drops
mixed into your colors will make them more transparent and radiant. Glaze
and layer with colors mixed with amber for a more 3 dimensional feeling
in your work. Pictures painted with amber do not require varnishing since
the color is protected by the resinous amber and the paint film becomes
plastic, neither brittle or friable. Amber is one of the finest varnishes
in the world today and may be used to protect painting as soon as the film
is dry to the touch. There is no need to wait 6 months since amber will
naturally contract with the painting. Just mix in with solvent and brush
on. After two coats your varnished painting will have a natural luminescence
and be protected for generations of enjoyment. Amber varnish is created
from 36% pure amber from the Baltic Sea, 36% purified poppyseed oil, and
28% Turpentine. You may use this varnish as a medium as well. Amber Painting
Solution medium is made up of 57% amber varnish, 16% Spic spirit and 27%
poppyseed oil. This product is not intended for varnishing. Blockx is the
only company that has sold amber for over 100 years and can guarantee time
tested results."
Definitely worth a try for those wanting to seriously emulate the Flemish
methods discussed in The History, Definitions, and Techniques of Oil Painting
section. Their claims to amber's plasticity are suspect considering the
resins long history of yellowing and cracking. In addition to that they
have mixed it with Poppyseed oil which, while being lighter in color than
linseed, is also less flexible, adding a double concern for cracking down
the road. The word that I have received is that the manufacturer expects
the artist to cut this mixture with an equal amount of stand oil (linseed)
and thin with turpentine before use as a medium. One might even want to
try it in smaller amounts than that. It should definitely be used on a
solid substrate rather than canvas. Blockx Amber can be purchased through
the Jerry's Catalog.
Another source for amber mediums and varnishes is Amber Alchemy Paints
and Varnishes. They also offer hisoric recipes of linseed oils and
mastic varnish mediums. Click
Here.
The same precautions should be taken as with the Blockx amber.
Amber, mastic, and sandarac are all reported to crack with the slightest
tap on canvas. Use only on panel or other solid support.
DRYING OILS and OLEORESINS
The following Drying Oils are available for the artist to mix his or
her own medium:
Stand Oil (preferred for mediums), Refined Linseed Oil, Cold
Pressed Linseed Oil (preferred as a vehicle for grinding pigments,
though Alkali Refined Linseed is more popular due to its light color),
Bleached Linseed Oil, Sun Thickened Linseed Oil, as well as Poppyseed Oil,
Walnut Oil, and Safflower Oil.
Lefranc and Bourgeois' Black (walnut) Oil dries through oxidation
when exposed to air. Black oil does not have a tendency to yellow which
makes it a highly reliable mixing oil. It may be worked in directly to
color or in combination with turpentine. When mixed with Black Oil, colors
develop a more durable, flexible paint film, allowing you to work the next
day without disturbing lower paint layers. A favorite of 15th Century painters.
Maimeri also offers a Walnut Oil.
Walnut oil can turn rancid, so don't buy more than you'll use in a relatively
short period of time. Otherwise it is a good drying oil. Since it is said
to yellow less than linseed, it may be good to mix with amber or copal
to reduce yellowing that may occur with these hard resins.
In the Oleoresin category, several manufacturers offer the balsam, Venetian
(or Venice) Turpentine, including Shiva, Rembrandt, and Sennelier.
It is not recommended that this balsam be thinned by more than 20%, nor
that it constitute more than 5% of the paint film according to Smith. But
Smith has an aversion to the use of any resin or oleoresin in mediums.
Other sources tell me that no such restrictions apply, though more than
20% is usually not necessary in a medium when mixed with oil, and extremely
high percentages of oleoresin would make the paint film dangerously resoluble
when cleaning. The judicious use of Venetian Turpentine will add lustre
and gloss to glazes.
A popular glaze medium using Venetian turpentine consists of
9 parts damar varnish (5 lb. cut)
9 parts turpentine
4 parts stand oil
2 parts Venice turpentine
For multiple layering add a little more stand oil to each layer.
This recipe will add gloss more safely than the use of a boiled oil hard
resin medium.
RESIN and other VARNISHES
Retouch Varnish is a highly thinned varnish meant to be applied
in extremely thin layers that should act more as a sizing to lessen the
absorbency and even out sheen, rather than as a continuous film layer.
If retouch varnish is applied too thickly in such a continuous film layer
it will add a complicating element to the physical structure of the painting.
The varnish should be completely dry before overpainting or the paint may
stay tacky for a long time. Sunken in areas may require more than one application
to bring them up to equal saturation and sheen with the rest of the picture.
It has been the general rule to let oil paintings cure for six to twelve
months before applying a Final Varnish. However, it has been said
that this is a holdover from the old use of heavy mastic varnish which
was practically poured over the painting. Today a painting of normal to
less than normal thickness paint films can be varnished in three to six
months with a thin varnish of damar. Synthetic varnishes may be able to
be applied sooner due to their greater flexibility. If underpainting is
cured, a glaze can be varnished as soon as it is dry to the touch. Ralph
Mayer argued that it is better to varnish too soon than not at all. A cracked
final varnish can always be removed and reapplied later, but damage to
the paint film itself may be harder to repair.
Damar can be purchased in crystal form and dissolved in Turpentine
to make your own varnish, or it can be purchased from a wide variety of
manufacturers in the form of a ready-to-use liquid varnish. Comes as a
final varnish for application after the painting has dried (5 lbs dry resin
dissolved in a gallon of solvent is called 5 lb. cut) and further dissolved
as a pre-mixed retouch varnish to brighten "sunken-in" areas
and protect new paintings. The final varnish can be used in painting medium
mixed up to 1:1 with a drying oil such as Stand Oil or Walnut Oil. As a
final varnish it is said to darken, but is resoluble and can (relatively)
easily be removed and a fresh coat reapplied. The longer that damar is
on a painting, the less soluble it becomes.
Old Holland offers a Mastic Resin Varnish as was reportedly used
by the Flemish and Italians in the 15th century and beyond. Mastic can
be used in recipes calling for amber, though it is a soft resin and is
therefore resoluble. As a final varnish it is more brittle and yellowing
than Damar.
Concrete Turpentine is now only available as Rosin for
polishing violins and for use in printmaking. This is not of the quality
of the "white varnish" used in the 15th century, as Rosin is
said to darken badly and become brittle. No one today recommends it for
artistic use. Whether Rosin could be effectively purified for artistic
use, I do not know; but the brittleness would still not recommend it for
permanent artistic use. It is considered an adulterant in paint and varnish.
Blockx Amber Varnish and Amber Alchemy Paints and Varnishes,
as listed above under mediums, are the only producers that I know of for
amber varnish.
Copal Resin, when it can be found, is today only used as an ingredient
in mediums, and not in final varnishes so far as I know. Quality is non-uniform.
Holbein's Painting Varnish - "a type of lustre oil. When
applied with Poppy Oil this varnish gives extreme brilliance to the picture.
The varnish increases the drying rate and gloss quality of your finished
paintings." The company does not list the ingredients in the promotional
literature that I have.
Conserve-Art is a superior quality varnish that is readily removable
over a long period of time with turpentine or any odorless turpentine substitute
without harming the original painting. The varnish dries quickly to a non-yellowing
film. Since it can be removed with an odorless turpentine substitute, it
may be a good final varnish over a painting that employed damar in its
medium (since such thinners do not dissolve damar.) This is most likely
a form of methacrylate (acrylic) varnish.
Daniel Smith Picture Varnish with UV-Absorber - This methacrylate
polymer works like a traditional picture varnish for oil, acrylic and alkyd
paintings. It contains an ultraviolet light absorber to inhibit fading.
Solvent-based, it thins and cleans up with pure gum turpentine only, dries
clear and is reversible with good quality pure gum turpentine only. Not
recommended to be applied greater than 1/8 inch thick. The UV-Absorber
may be beneficial applied over resins and oils known to yellow.
Gamvar by Gamblin Artists Colors is a low molecular weight (LMV)
synthetic resin varnish that has a refractive index similar to damar natural
resin varnish. Adding it as the top layer will saturate the colors of your
paintings and intensify the transparency of your glazes. Gamvar contains
an ultraviolet light stabilizer that protects your paintings from UV Radiation.
Gamvar is water clear. Artificial aging studies have demonstrated that
it will not yellow over time. Gamvar is a good varnish from a painter's
point of view because your paintings will look beautiful today. From a
conservator's point of view, Gamvar is a good varnish because they will
be able to clean your painting in 100 years without using such strong solvent
that they may harm the paint layers underneath.
The formula for LMW Resin Varnish with a UV inhibitor was first published
by the head of conservation science at the National Gallery, Rene de la
Rie. Robert Gamblin was so impressed by its qualities that he asked if
he could produce and sell such a varnish for artist use. An agreement was
reached to allow the commercial production and sale of this resin as Gamvar
with a portion of the profits donated to the Conservation laboratory of
the National Gallery of Art to support research on contemporary painting
and painting materials.
SICCATIVES
Quick drying additives have been used to speed the drying of paint films
since oils were first used to paint. A Number of the classic dryers are
mentioned above in pre-prepared mediums such as
Siccative of Haarlem.
Siccative dryers that can be purchased on the market to add to your
own glaze medium include:
Lefranc & Bourgeois White Courtrai Drier - used to make photo
retouch colors, this siccative hardens the paint film rather than making
the color dry more quickly. This colorless siccative does not alter the
hues of lighter colors according to the manufacturer. Historically, courtrai
drier has darkened and cracked.
Daniel Smith Cobalt Drier is a viscid purple liquid that works
by attracting oxygen more quickly to the paint film. Made by cooking cobalt
salts in linseed oil, it should be used sparingly (not more than 5%). Since
the 1850s, cobalt drier has proven useful when added to glazing mediums
containing stand oil, pure gum turpentine and damar varnish. Cobalt drier
is said to be the least harmful natural drier to use in glazing mediums.
Alkyd Medium - this linseed oil modified alcohol-acid synthetic
resin is quickly becoming the favorite of artists to speed drying. Having
linseed oil as its base, it is compatible with all oil colors, does not
show the tendency to discolor or crack, and will not continue oxidation
of the paint film beyond its proper drying level. Sold by Winsor &
Newton as Liquin.
DILUENTS
Thinners are available in old and newer formulas:
English Distilled Turpentine, Triple Rectified Turpentine, or 100% Pure
Gum Turpentine listings for artist use: best quality and highly refined.
Best overall diluent and number one choice for serious artists.
Mineral Spirits: You can substitute this petroleum hydrocarbon
for turpentine in all painting functions which do not include damar --
it's a practical alternative for paint thinning and general clean-up. Be
sure to have adequate ventilation when working with mineral spirits.
Lefranc & Bourgeois Quick Drying Petroleum - evaporates completely
leaving no trace since it is not greasy and no oxidation takes place. It
penetrates and seeps deeply into the paint, making it very fluid and mobile.
A True Petroleum distillate will dissolve damar -inquire from the reseller.
Turpenoid: An odorless turpentine substitute, it has the same
painting properties and drying time as turpentine, but is free from the
strong characteristic turpentine odor. Good for thinning oil colors and
cleaning brushes. Will not dissolve damar so it cannot be used to mix varnish
or resin medium.
Turpenoid Natural: Non-toxic, safe, brush cleaner and thinner
formulated from natural essence of citrus products and other natural sources.
Safe to use and safe for the environment. Turpenoid natural is the clear
choice for the oil painter concerned with the health issues related to
Turpentine. Not recommended for mixing in greater than a 50/50 ratio to
color and will not dissolve resins such as damar.
(**this product should not be confused with Turpenoid above. Unlike the
product above which evaporates completely, Turpenoid Natural appears to
be oily and slick when mixed with oils as a thinner/medium and displays
noticable brush strokes.)
Eco-House Solvents #115 Extra Mild Citrus Thinner can be used
to clean up and thin oil paints, but will not dissolve damar resin. Made
from natural oil peel and mineral oil.
#915 Natural Orange Terpene Solvent is a potent solvent that
will substitute for Turpentine and can dissolve damar resin. Use only in
very well ventilated areas. (don't let the citrus smell of some of these
solvents fool you - they are dangerous)
I'm not sure if the Oil of Spike Lavender listed in mediums (above)
has other additives, but if pure, it also works as a diluent and was widely
used in the middle ages. Dries more slowly than Turpentine, allowing the
artist to work wet in wet.