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Oils and Alkyds As binders for making paints
Drying oils, especially Linseed Oil, have been known since the earliest
recorded times, but 3 things worked against it's adoption as the
popular painting medium we know today. Firstly refining techniques were
poor and the oil was thick and mucilaginous, secondly artist's were
very happy with the primary painting medium of the day which was
Encaustic. Seeing the work of modern Encaustic masters like Jasper
Johns one can see why, and thirdly the distilling of Turpentine had not
been invented yet. It wasn't until the 14th century that the modern day
refined Linseed Oil was developed, Turpentine was now available, and it
was the Renaissance, artists were ready for a new approach to making
art. Oil Painting as we understand it was born. The next 700 years saw
new pigments, and new implements like flat brushes but the oil stayed
essentially the same until the 1960's when Alkyd Oils were developed
for the automotive and industrial paints industry. Those industries
have now become almost 100% based on the new Alkyd technology, only
artist's still keep the Linseed Oil tradition alive. Alkyds have had a
major impact on artist's (so far) in the form of mediums to add to
conventional oil paint, but Alkyd paints as such have been slower on
the uptake, and the signs are that that will remain the case in the
foreseeable future.
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Acrylic binders
Gums
Eggs
Waxes and natural resins
Cold pressed Linseed oil The
best grinding oil
By far the best oil for grinding pigments into it has many
advantages. It has a high acid number which imparts desirable
qualities. Firstly it is more stable as to color. Just because an oil
has a certain color when new and liquid does not mean that it will
remain so throughout its life as a dried paint film. Cold Pressed oil
seems to be particularly stable in this regard. It also produces a more
flexible and durable paint film. When grinding it has superior wetting
power. It should be first choice for making paint in the studio. There
are two types on the market, distinguished by their origins.
Cold Pressed in a
windmill on stone mills
This type is the most like the oil used by the old masters. It is also
the least efficient method possible and consequently is the most costly
oil. I am only aware of one company selling it Old Holland, which
claims to be the oldest paint manufacturer in the world and the only
one using the oldest techniques of manufacture. Their Linseed Oil from
the windmill is noticeably different from all other oils including the
industrially produced Cold Pressed oils.
Industrially Cold
Pressed Linseed Oil.
Other brands of Cold Pressed Linseed Oil on the market are noticeably
lighter and I have no reason to believe they are in any way inferior to
the windmill Cold Pressed oil. It is generally easy to obtain from all
major artist's supply stores.
It is important to consider the opinions of Linseed Oil manufacturers
as detailed below in the Alkali Refined Linseed Oil section in regard
to Cold Pressed oils. They believe that The Alkali Refined is superior
and present it to artist's materials manufacturers in that light. The
above comments are based purely on the accumulated experience of
artist's themselves and is backed up by all major artist's materials
authorities such as Ralph Mayer. My own experience supports the
excellent qualities of the Cold Pressed oils, and I suspect that the
big oil manufacturers are actually relying on information relating to
industrial paints and have done little if any research into the actual
needs of the economically insignificant artist's paints. There is huge
economic benefit to the Linseed oil maker to have the whole world use
their Hot Pressed products.
Alkali Refined Linseed Oil Hot
Pressed oils
By using heat during oil extraction a far larger portion of oil is
extracted from the seed. This process first started in the 19th century
and is the industry standard. Most artist's oil colors sold that are
ground in Linseed Oil, are ground in Alkali Refined oil. The large oil
manufacturers have invested large amounts of money for over a hundred
years into research on better methods of oil production and the
problems with early Hot Pressed oils were largely overcome by using
alkali during manufacture instead of acids for the best grades. They
claim that it is superior to the Cold Pressed oils in overall
qualities, and they claim to have research that backs the claims. On
the other hand that research looks at such 'qualities' as economic
viability, ease of manufacture and other parameters that artist's don't
often consider as being as important as most other industries do. On
the other hand, they are expert in their field. the individual artist
must make their decisions on what is the best oil to use based on their
needs and factoring in all the arguments both ways.
it is common practice to bleach these oils chemically, but the best
grades are bleached using superheated steam and refrigeration and
these oils have superior color stability to other Alkali Refined oils.
Even so it is a good rule of thumb to assume that the palest versions
of the oil will darken more with time, and that the deeper colored
oils will change less. so that the end result is similar. Alkali
Refined Linseed Oil should be regarded as second choice, for use when
Cold Pressed is unavailable.
Sun Bleached Linseed Oil An
old process
The old masters often used this oil and it is a refining process that
can be carried out in the studio by the artist or purchased as it is
commonly available still, although there is no guarantee that the
purchased product is made from Cold Pressed oil, and in fact is likely
not to be. While it has been long used it is believed to produce an oil
with similar properties to Blown Oil (see below) including its defects.
The sun bleaching process increases the oil's drying speed and leveling
qualities, but also creates such undesirable qualities as to reduce its
wetting abilities and otherwise render it less desirable for grinding
paint. Its use should be restricted to use in painting mediums and
varnishes, and for glazing where the underlying layers are well dry.
To make Sun Bleached Linseed Oil mix it with water (salt or fresh)
about 50 / 50 and shake the 2 together in a jar then expose to sunlight
for several weeks. It needs to be covered so that dust is excluded but
air it admitted. Too much air thickens the oil too much. The time for
bleaching varies according to season and location. Putting a little
clean sand in the mix at the beginning to help promote the settling of
impurities, and the oil will require filtering at the end of the
process. Separator funnels can be obtained from laboratory supply
firms for separating the oil and water at the end. Do not bleach too
much as it is possible to bleach to a point where the oil will
eventually revert to a darker color than it started as. The optimum
bleached color is a light golden color.
Hardware store Linseed Oil Bad
news oil
Linseed oil sold in hardware stores is intended to be used for treating
wood and other applications that do not involve color permanence. Low
price is an important consideration as this oil is often used by the
gallon, and the low price is attractive to poor artist's. it is
advisable to resist the temptation of price as these oils have numerous
defects for artist's use. There are 3 main types that are available:
Raw Linseed Oil
This is Hot Pressed oil which is warmed and then simply left to stand
for a period while the sediments (called 'foots') settle. It is a dark
oil, cheap to make which has only one advantage, that of durability
which makes it popular for treating bare timber and making industrial
coatings. It should never be used by any artist wanting their paintings
to last as it will darken with time.
Boiled Oil
This is Raw Oil that has driers added. The better grades are heated as
well to thicken the oil. The driers make a poor oil even worse in terms
of permanency of artist's paints. Unwise to use.
Blown Oil
This oil is polymerized by blowing air through the oil. This process
thickens the oil which is useful for many industrial purposes, but can
have a poor result if used for making artist's colors.
Stand Oil Great oil, but
not for paint making
Stand oil is probably the least yellowing of the Linseed oils but that
is not enough to make this a good oil for grinding pigments in. It has
excellent leveling properties, which means it doesn't leave brush
marks,
and is slow drying. It will impart these properties to any paint made
with it. Use it for glazing, where it is the perfect oil, and never use
it to make paint.
Poppy Oil The non
yellowing alternative
Often used, especially for whites and other light colors Poppy Oil has
never the less always played second fiddle to Linseed oil for good
reason. While it is naturally a pale yellow or is almost colorless, it
has other problems. it has a far greater tendency to crack than Linseed
Oil, and is slower drying. Only one major manufacturer grinds all of
their colors in Poppy oil but many others grind the light colors in
Poppy as the light colored oil makes the paint look brighter straight
from the tube. manufacturers also like the ability of Poppy oil to
produce buttery paint easily.
On the other hand the long term durability of these paints is not as
good as Linseed Oil paints and while they start very pale. Poppy oils
are known to yellow with age, although perhaps a little less so than
Linseed Oil. it is the drying speed and lack of long term flexibility
that are of greater concern however, and painting with oil paints
ground in Poppy Oil requires careful attention to sound traditional
painting practices to ensure maximum longevity of the work. With such
care however Poppy Oil can be used with confidence as a useful
alternative to Linseed Oil.
Nut Oil Made from English
Walnut kernels
In use from the earliest times of Oil Paint usage this was the favored
oil of Leonardo da Vinci. Despite this recommendation, and the fact
that this was a commonly used oil in the early times and has been
argued to be superior to Poppy Oil, this oil is not so commonly used
today. This may be due to high cost which has prevented it being used
in industry which has usually been the driving force for research and
popularization of other products. it has similar properties to Poppy
Oil, but has the advantage of faster drying. Overall, however, it is
considered inferior to Linseed Oil in terms of long term durability,
although approximately the equal of Poppy Oil. In that case its faster
drying would suggest it would be used more than it is, and perhaps
unfamiliarity as well as cost and availability are the factors at work
here.
Hempseed Oil Historic
interest only
Hempseed Oil was used in the early days of Oil Painting as an
alternative to Linseed Oil. it has properties similar to, but inferior
to Poppy Oil. it should not be considered for permanent painting.
Safflower Oil Becoming more
common
Some of the largest artist's materials manufacturers are using this oil
to grind the whites and some light colors and blues. it is used in
industrial paints as it has a good reputation as non yellowing. It is a
common ingredient in Alkyd Resin paints and is used in large quantities
industrially. it is generally considered inferior to Linseed Oil in
terms of long term durability as the paint film is likely to become
brittle with time.
Sunflower Oil Another
industrial product
Sunflower Oil is similar to Hempseed Oil in general properties and is
sometimes used as a Linseed Oil substitute, but not by artist's
expecting to make permanent paints. Often used, especially for
whites and other light colors Poppy Oil has
never the less always played second fiddle to Linseed oil for good
reason. While it is naturally a pale yellow or is almost colorless, it
has other problems. it has a far greater tendency to crack than Linseed
Oil, and is slower drying. Only one major manufacturer grinds all of
their colors in Poppy oil but many others grind the light colors in
Poppy as the light colored oil makes the paint look brighter straight
from the tube. manufacturers also like the ability of Poppy oil to
produce buttery paint easily.
On the other hand the long term durability of these paints is not as
good as Linseed Oil paints and while they start very pale. Poppy oils
are known to yellow with age, although perhaps a little less so than
Linseed Oil. it is the drying speed and lack of long term flexibility
that are of greater concern however, and painting with oil paints
ground in Poppy Oil requires careful attention to sound traditional
painting practices to ensure maximum longevity of the work. With such
care however Poppy Oil can be used with confidence as a useful
alternative to Linseed Oil.
Alkyd Oil-modified Resins Fast
drying alternatives
Alkyd oil-modified resins are unusual in this list in that the oil
becomes an integral part of the resin molecule as a result of the
manufacturing process. The oils used can be various, Safflower and soya
are very common, but it can also be made with Linseed Oil and this
Linseed Oil version is not surprisingly, the most durable. It has the
disadvantage as with the traditional form of the oil that it is likely
to yellow more however. Alkyd Oil-modified Resins have unique
properties that have seen them almost totally replace traditional
Linseed Oil as the primary house painting and industrial paint oil.
Their most obvious characteristic, that of extremely rapid drying has
resulted in a less rapid acceptance in the fine arts, where slow drying
in oil is often seen as an advantage. However they have become a
popular painting medium where the advantages of Alkyd can be easily
balanced with the advantages of traditional oils for a compromise paint
that suits many artist's.
Utilizing Alkyds as a basic material for grinding pigments is best left
to the experts but there is no reason why grinding colors into the
prepared Alkyd mediums sold in art store cannot be experimented with.
There are several available with various properties but as a guide I
might mention Liquin and Oleopasto both made by Winsor and Newton as
examples of a thicker and thinner Alkyd medium that might be a good
starting point.
References
Alberti, L B, On Painting 1435
(Penguin Classics)
Cellini, B, The Life Of Benvenuto
Cellini, finished 1562 but not published until 1730
(Heron)
Cennini, C d'A, The Craftsman's
Handbook. 1437 (Dover)
Doerner, M, The Materials Of The Artist And Their Use
In Painting, 1921 (Harcourt Brace)
Eastlake, Sir C L, Materials For A History Of Oil
Painting, 1847 (Dover)
Feller, R L, Artists Pigments 1986
(National Gallery Of Art / Cambridge University)
Gottsegen, M D, A Manual Of Painting Materials And
Techniques, 1987 (Harper & Row)
Maire, F, Colors: What They Are And What To Expect Of
Them, 1910 (Drake)
Mayer, R, The Artists Handbook Of Materials And
Techniques, fifth edition 1991 (Faber
& Faber)
Merrifield, Mrs M P, Medieval And Renaissance Treatises On
The Arts Of Painting 1849 (Dover)
Muther, R, The History Of Painting From The Fourth
Century To The Early Nineteenth Century, 1907 (Putnam)
Parkhurst, D B, The Painter In Oil 1898
(Lothrop, Lee & Shepard)
Patton, T C, Pigment Handbook, 1973
(Wiley)
Pliny, The Elder (Gaius Plinius), Natural
History, 77AD (Penguin Classics)
Taubs, F, A Guide To Traditional And Modern Painting
Methods, 1963 (Thames & Hudson)
Theophilus, On Divers Arts, 1125 (Dover)
Various, Encyclopedia Britannica,
fifteenth edition 1981 (Encyclopeadia Britannica, Inc)
Various, Paint And Painting, 1982,
(Winsor & Newton / The Tate Gallery)
Various, The Artist's Colourmen's
Story, 1984 (Winsor & Newton)
Vasari, G, The Lives Of The Most Excellent Painters,
Sculptors And Architects, 1568 (Penguin Classics)
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