dk nkf - Nordisk Konservatorforbund Danmark

twentieth century. In the same period, the red
and yellow organic pigments were unpopular
for outdoor purposes, as they had poorer weather
resistance than inorganic pigments [9]. Almost all
the different classes of synthetic organic pigments
were developed before 1970 [10]. In 1927, which is
a focus year of Den Gamle By, the synthetic organic
pigments existing were a wide variety of red, orange
and yellow colours [11] as well as a single blue and
green pigment [12].
Inorganic pigments
Although the number of inorganic pigments in use
has declined during the twentieth century due to the
development of many synthetic organic pigments,
titanium dioxide white, carbon black, iron oxides etc.
are used in huge amounts. Before health and safety
became an issue many harmful inorganic pigments
were widely employed. In 1927, this included zinc
green and yellow (containing chrome), chrome
orange and yellow (containing lead) and of course
the important red lead and lead white. Unlike other
countries, such as Sweden, Denmark did not legislate
in accordance with the Geneva Convention of 1921,
which strongly limited the use of lead in paints and
varnishes. The only limitation of the Danish law of
1925 was a ban against grinding and polishing dry lead
paints. Due to the availability of other white pigments,
lead white was not widely used by house painters at
the time, but the use of other lead containing pigments
was still extensive [13]. Until 2001, it was still legal
to sell lead containing paints in Denmark, and in fact,
due to an exception in the law, it is still legal to use
red lead on historic objects [14]. In the second half of
the twentieth century, zinc chromates gradually took
over the important role of red lead for metal primers.
Though toxic itself, it is not banned.
The pigment titanium dioxide white has truly
become a giant in the paint industry. It entered the
Danish market in 1920, but the Danish painters
were suspicious and therefore reluctant to use
it in the beginning [15]. By the mid 1920s, the
painters eventually acknowledged the qualities of
the pigment and it became popular for high quality
work. Bear in mind that the pigment was a mixture
of titanium dioxide (>18%), zinc white and blanc
fixe [16]. For less important work the white pigment
lithopone was used. The first titanium dioxide was
an anatase crystaline modification. Around 1950,
the rutile modification was introduced to the market,
providing better resistance to weathering. Later,
coated titanium dioxides of various kinds were
developed [17].
In the 1920s iron oxides were sold, but had not yet
substituted the natural earth colours of yellow, red
and brown [16]. In the second half of the century,
these natural earth colours no longer had any
extensive use.
Extenders
Most extenders of paint have been in use during
the entire twentieth century. They are not toxic,
and therefore not problematic in reconstructions.
Important extenders are chalk, china clay, talc, blanc
fixe (especially in the first half of the century) and
mica [7,17,18].
Methods of application
By the beginning of the twentieth century, all
application was done by brush. Around 1910 the
air brush was introduced to the Danish market, but
this method was still relatively rare by the end of
the 1920s [16,19,20]. Later, air brushing became a
standard method of application, and different types
of equipment were invented. It is possibly the most
important industrial mode of application today. By the
1940s, the methods of application included dipping
(high viscosity and thick layers) and covering objects
in paint in a spinning drum (low viscosity and thin
layers) and other less important processes [21]. The
roller for house painters was introduced quite late in
Denmark, many years after the introduction in other
Northern European countries [22]. Stelling began
producing and selling rollers in 1953 or 1954. In the
book “Malerens bog” from 1954, an entire chapter
is devoted to the instruction in the use of the new
roller [23,24]. This seems superfluous today, when
everybody employs rollers without any instruction!
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