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| Florentine frames |
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Florentine Frames
in the Middle Ages and the Renaissance
TYPES
Picture frames have accompanied the many different forms of
figurative art from earliest times, as most artists have always
preferred to isolate their work from the surrounding environment. This
is why the scenes frescoed on church walls were divided by decorative
friezes that the painter himself designed and by motifs that were often
suggested by their architectural setting.The first mobile painted works
were created in the 13th century. Realised in tempera on a gilded
background, these paintings on wood were designed to decorate the
altars of the new cathedrals that were being built in all the larger
towns and cities in this period. The altarpieces were originally always
on a cusped design and formed structurally of pieces of wood held
together with transversal joints placed on the rear, fixed directly
onto the wood with nails. The frame was therefore born from the
necessity of consolidating the edges of the painting and also to hide
the thickness of the wood. A finishing surround was created by applying
one or more strips directly to the flat plane of the wood, sometimes
strengthened by an external reglet that was placed transversally across
the painting.
13th century frames were very simple mouldings that
projected very little. The frames that were created in the century that
followed were transformed into independent structural elements, rich in
carvings and fretwork, decorated with small spiral columns and topped
with capitals and foliage-scrolls. This sort of frame was usually used
for the polyptyches, whose often very elaborate structures were closely
linked to the architecture of the period, especially the aedicolas and
the niches that were being opened in the walls of the churches and
other buildings. Even the carpentry used to assemble the polyptych was
almost a work of architecture with complex jointures that linked up
paintings carried out on separate pieces of wood.
Thus the difficult
technical problems related to the realisation of large painted works on
wood were also finally resolved as this material was continuously
subject to variations in size. Joined together in a frame, the single
panels could more easily stand up to the effects that the changes in
temperature could have on the material, without compromising the
composition as a whole.This type of structure remained more or less
unchanged until the mid 15th century, though it followed the various
trends in Gothic architecture. During the Renaissance, frames were
again aligned with the formal models introduced by Filippo Brunelleschi
to architectural design in Florence. In this period a single pictorial
composition, conceived on the Renaissance idea of a unitary view,
became more popular, rather than the painting being divided up into
several parts. It was then framed in solid wooden structure formed of
linear trabeations held up by pilasters and decorated with motifs taken
from classical themes instead of acute arches and Gothic
decorations.The great success encountered by the new decorative models
led to many of the polyptyches carried out in the previous century
being dismantled and adapted to fit new frames.
The simple box frame,
still in use, appeared in the second half of the 15th century with the
birth of the painting of profane subjects and above all portraits.
These works naturally did not require sumptuous carved frames like
those adopted for the paintings decorating church altars. This type of
frame structure was formed of a rectangular framework around the edges
of the painting to which the mouldings were applied: the internal frame
(called "alla battuta") served to keep the picture in place, while the
external one (called "al profilo") had a purely decorative function.
This model continued to be used for all the centuries that followed,
varying in some of the single details and decorations according to
changes in taste and fashion. Apart from these more common models, more
elaborate frames were produced during the 16th century to surround
paintings of greater importance. These were usually called gallery
frames and included the much used round frames and the Sansovinian
frames. The round frame possibly takes its origin from the "desco da
parto", though more probably from the circular "eyes" typical of
Brunelleschi's architecture and was generally decorated with festoons
of leaves and fruit, very similar to those in the Della Robbia glazed
terracottas. Although the production of round frames had already ceased
by the second half of the 16th century, Sansovinian frames, elaborated
by the Venetian school, but only distantly related to the type used in
Florence, remained in use for the whole of the century that followed.
They took their name from the architect Jacopo Tatti, known as
Sansovino, who was Tuscan, but active for many years in Venice.
The type of frame developed by his entourage was characterised by an
abundance of decorative and classically influenced motifs, partly
superimposed, with pairs of caryatids or hermae at the sides to support
the upper part of the structure.
EXECUTIVE TECHNIQUES
The oldest frames were formed of
simple mouldings created with the same wood as the altarpiece or applied
directly onto the wood of the painting
itself.They were already
enriched with decorations in relief from Gothic times, either in carving
or carried out by applying and modelling plaster, a mixture of
scagliola gypsum and starch paste that was used a great deal in the 18th
century for the "rocaille" type of decoration.
The wooden
surface of the frame, whatever the type, can be simply decorated in
tempera or covered in gold or silver leaf or silver varnish.
Gouache
gilding
This technique was carried out by following a series of
operations:
a) First it was primed, in other words, the surface was
covered with a layer of gold gypsum dissolved in animal glue in order
to create the right hydrous balance with the materials successively
placed on top.
b) Next it was given a layer of Armenian bole, a mineral
that, when mixed with animal glue, is capable of gradually and
permanently losing its water molecules and, once it has completely
dehydrated, assuming highly adhesive properties. Armenian bole comes
in various colours, the choice of colour depending on the level of
transparency required for the gilding. Up until the 15th century,
yellow bole was used for the initial layers, followed by other types of
red or dark brown bole, to which the gold leaf was then applied.
c)
Then gold leaf was applied to the surfaces prepared with the bole and well
dampened with water.
d) It was then burnished, an operation carried
out with an instrument made with a hard stone (generally agate) fixed onto
a wooden handle. The pressure made the gold leaf adhere perfectly and
gave the gilded surface a shiny and brilliant aspect.
e) Lastly it was
engraved, a finishing operation that consisted in decorating the
already gilded surface with impressions carried out with a hard point so
as to obtain a contrasting effect with the smooth surface. The
instrument used was the graving tool, which comes in various shapes and
sizes and has a pointed tip in metal, agate or bone.
Silvering
The
procedure of the application of silver leaf onto the wooden surface is the
same as that indicated for gouache gilding; the only difference is
that water is not enough to help it to adhere to the layer of bole,
because silver leaf is thicker and therefore not as malleable as gold
leaf, so a glue, normally of animal origin, had to be used as well.
Silver
leaf could also be burnished and, as it tended oxidise when in contact
with the air, it was protected with a layer of transparent varnish.
Silver
gilding varnishing
Silver leaf was often used, basically because of its
cost, in the place of gold leaf and the surface was treated afterwards
with a special yellow coloured varnish, known as "mecca" or
silver gilding varnish. This treatment gave the silver leaf the same
effect as the more expensive gold leaf. A mixture of the following
vegetable resins were used to make this varnish for gilding silver:
the main components were sandarac, diluted in alcohol;
golden yellow
gambode, diluted in alcohol and added in small doses to avoid the
yellow colouring from becoming to strong;
dragon's blood, a dark red
coloured resin, also diluted in alcohol, that gave the solution an
orange-red colour;
aloe, a greenish brown coloured vegetable resin that,
greatly diluted, was added to the other mixtures until the required
shade was obtained.
Tempera decoration
Frames often were often
carried out with some parts gilded and others coloured with tempera. Tempera
was made by mixing natural earths with animal glues; alcohol was then
added to help the colour to adhere and it was spread on a surface of
three or four layers of really smooth plaster; after this treatment, the
layer of colour could be burnished to
obtain a final shiny surface.
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