domingo, 31 de agosto de 2008
Age can been approximated by various details in design and construction, a knowledge of this will give rise to a more sympathetic restoration and one that can be quicker and easier to perform. If you are aware of the date for different forms of casting materials it will follow that you can have an idea of the age of a cannon or brass telescope, also it will be apparent in the style of an oak chest, done without any glue being used, the approximate age, the cutting of veneers is another example, the reduction and scarcity of exotic woods started to create a market for veneers and the finer the veneer the more could be extracted from the rare source material. The development of the nail and screw, from blacksmith wrought to engineers turnings gave signs for one to assess the age of furniture, this is why a restorer keeps all the old nails and screws that he/she comes across, it is even more necessary now since the availability of the common screw is itself threatened by the philips or posi drive.
A normal way to judge any antique is to pick it up and feel its presence, touching an object can gives instant indication of its material, texture, density and weight, with wood, the colder it may feel can give the impression of more density, heaviness, with visual appearance this can be a sign of more mature timber and more age, the passing of your fingers over the surface will give an idea of the grain's texture, type of wood and its age may again be established when added to the visual inspection, finer grain may be true of a longer growing period and older variety of a species of timber. The fingers will also pick up tell tale signs of previous repairs and changes in polish or laquers.
Knowledge of different timbers can be useful in assessing types of glue that are practical and how certain polishes will take to the surface, it may be necessary to de grease timber or roughen it in order for glue to hold. Antique mahogany very often had virtually one coat of polish or just oil, as a means of enhancing the grain, whilst the Victorian period needed to apply possibly seven or more coats on top of flling the grain with plaster of Paris, the later timber was so open that it needed to be filled and still it would absorb huge amounts of the shellac polish.
It is often the case that your only contact with the origional makers or artists, is with their work, this can, if you wish, have an intimacy , for you will see far more of their marking out, mistakes and style of construction or painting that is solely their own, often you will see the small marks of a chisel or marking gauge, the difference of one maker to another with the shape of a curve, which can also be indicative of age, as is evident in the changing styles that can be seen in front legs of a chair and table legs.
The concept of patina and its association with age is worth remembering when re polishing furniture or cleaning paintings, it is not necessarily good to remove all signs of age but it may well be worth clearing the cloudiness of a shellac polish for the true colour and grain to be appreciated. The refractoriness of a shellac polish, alters with age and when the light can no longer pass through the once transparent layer, it is reflected as a white or bleached look. Some times we may well be valuing the age of an object and not its aesthetics, early veneered pieces where often made to be, by our tastes now, very bright and gaudy but time as tamed them behind a cloudy varnish, we are used to them as pale objects, yet if they are cleaned and the polish is revitalised, there can appear an all too different beast, this has been the start of many arguments in the field of restoration with paintings, for many centuries the restorer was aware of the likely controversy, cleaning would have, so they would clean and then re varnish with a tinted varnish so to not offend the viewer.
The appreciation of art is not always clear and it is shown in a short note about Shelley, whilst touring in Italy. 'travelling in Italy, he arrived at a convent just as the village plumber, glazier and painter(house), was withdrawing his workmen from their task of touching up the old masters,which operation had been included in the contract for renovating the paint and whitewash of the Holy edifice'
A note about fillers, gesso is historically used as a base for paintings, like most things with paintings, the process often then gets passed to furniture, the lifting, relining and transferring of paintings was done far earlier than the use of veneers on furniture but the veneer is glued with the same process as the early artist/ restorer used to remount the ageing canvas. Gesso with animal glue is the base for paintings and often used as a base for furniture that requires a high lacquer finish, plaster of Paris, if mixed and spread over the timber will, once thoroughly dry, take polish on top of it and become transparent as it absorbs the shellac, or can be stained with the whole of the piece before polishing, I often seal timber with a thin coating of animal glue before staining ,so as to limit the stains effect on the changing direction of grain, going darker into the end grain and staying pale on the side of the fibres, this is another point when staining, to slightly roughen the grain in order to get a more even colour. A gesso paste can be made from- white lead, some ochre, oil varnish(siccatif de courfrais) resin and turpentine oil, after drying the gesso must be sanded and when dry, coated with a 10% size solution( animal glue that is diluted so that it is more of the consistency of yoghurt) to prepare the gesso, a small quantity of the glue size is placed o a roughened thick glass palette, alabaster plaster is then added until, after working with a palette knife, it forms a firm, barely malleable paste, care being taken not to arrive at a gesso that does not correspond to the area to be repaired, not to be darker than its surrounding, for light areas white pigment is added and for darker areas, more ochre. Finally some amber varnish is added in small quantities, constantly mixing to form an easily malleable paste. A horn palette knife or spatula is used to firmly and precisely spread the paste into the defective areas, completing the process with a little water to smooth out the final surface, on paintings it will be necessary to wipe the surface with a moist cloth so as to leave the gesso only in the areas of damage and not on any of the paint. This gesso will hardly shrink, should remain firm but porous, its absorbency making it ready to accept further treatment, it is possibly best to let the gesso sit very slightly below the true level so as to allow varnish and paint to be applied up to the true level.
An assistant some years ago remarked, on seeing me use saliva as a vehicle whilst restoring a piece of furniture, that it was highly unprofessional, and when I asked why, he said that most of what he saw me do was not to be found in any of the books that he had read or at the college that he had been . I remarked to him that there can be certain limits to the amount of knowledge he may find in books and that it is always a case of learning first and discarding afterwards, he was welcome to use or discard what ever he saw me do but as my knowledge spanned more than thirty years it was worth considering why I did what I did. Linseed oil, resin, mastic varnish, copal, lavender oil, lye, butter, common wood ash and even soil, where used in the cleaning of paintings, to brighten the paintings, certainly it is not advisable to copy all these but it is worth considering why they might work and where you can use them safely. Spit is a very good cleaner and will dissolve grease and dirt a lot quicker than many propriety cleaners, a lot safer as well, the artist often used egg white as the only means of getting an even glaze to a new painting before it had time for the paint itself to harden, which could be several months to a year, using a varnish too early on would coarse the paint to remain liquid beneath a sealed coating where as the egg would prevent dust and smoke sticking to the fresh oil paint and still allow the oils to dry naturally.
Varnish-middle English vernisshe, from Old French vernis, from Medieval Latin veronix, vernix, sandarac resin, from Medieval Greek verenikē, from Greek Berenikē, Berenice (Benghazi), an ancient city of Cyrenaica.]
Copal, is a slow drying resin, several species of the genus Copaifera, the trees of the Leguminosae family, growing in the tropical regions of the Americas. Deep incisions, canals( similar to those made for extracting latex) are cut into the bark and the balsam flows as does the turpentine of the pine tree, another natural oil ( not to be misconstrued with the white spirit that is sold as a cleaner)
Copal is made up of solid resins and etheral oils, this is similar to resin varnishes, which are a solution of mastic, or Damar resin(resin from India) in oil of turpentine. Genuine copal has a consistency of fatty oil but does not contain oil for the purpose of painting or conservation. When heated in a porcelain bowl, it should not give off any odour of turpentine, and on cooling should be a transparent, brittle resin.
Copal for balsam( para balsam) and the more viscous (maracaibo balsam) differing in the content of etheral oil, the para balsam will change to the maracaibo if left to stand in contact with the air for a long time, or by boiling with water. Copal as low tension properties, and slow drying, turpentine oil is on the other hand has a tendency to evaporate quickly at low temperatures and will have higher tension; copal, heated in a retort over water,will stay virtually unchanged after cooling,while, under the same conditions, conventional resins and that of turpentine will solidify. Contrary to this, linseed and poppy oils are used in the making of oil paint because of their tendency to dry quickly.
quarta-feira, 13 de agosto de 2008
It may be that before 1800 the painter was an artisan first and his studio a workshop with apprentices and craftsman alike working together in their expectation of producing work that would last many centuries, they produced their own colours, made their own grounds and passed on their knowledge to their students, all with the aim of continuing a tradition for employment, the only possible reservation was to have kept this within the confines of the town or city. Later artists had developed a more insular approach and with it have come the development of the brush, paint, varnish maker, framer and guilder, all separate entireties and all possibly subject to other market forces that may create the need for economy of materials or the vagaries of a market force with supply and demand adjusting price. This off the shelf approach would certainly have led to the artist being separated from intimate knowledge of his materials, especially the quality and content of the materials, also the painter gradually became less concerned with the quality or the longevity of his/her work, not appreciating the re sale but only the initial sale value, leaving others to find that they had bought a painting that now required maintenance, a very good example of this was the painter William Turner, whose almost cavalier attitude to paint and its application, led to his works cracking and flaking within months of their completion, thankfully his drawings and water colours where free from these problems. The earlier painter, by over three hundred years, Van Eyck whilst developing and learning the process of painting in oils, produced such quality paintings that they are now among the most well preserved of all art, sadly the expertise that he and his brother developed went to the apprentices but does not seem to have travelled beyond and saved the rest of art from the vagaries of bad technique and poor quality paints.
It is difficult to think how works of art before 1700, largely religious subjects and commissions, would have survived without them undergoing restoration, retouching or repainting, the continuance of style change and the gradual change of emphasis within the church, will have led to many paintings being up dated, given altered prominence and fresh adornment, provided by eager young artists that would need new commissions and seek fame. This would be for the church and the artists an ongoing work of art, almost seen as unfinished and certainly not the ownership of the original artist, the extreme of this can be seen in the ‘Guilio 11’ statue, by Michelangelo, becoming the ‘ Guilio Canon’.
The sensitivity of the eye and the ear has become something of a daily demonstration to me, with an almost loss of sight in the right eye, which is progressing well at the moment, and the diminished sight in the left eye, no longer able to improve the state of this eye, I have become aware that my hearing has adapted quickly , becoming more responsive and giving me more special awareness that seemed before to be the priority of my eyes.
My experiences whilst working for the theatre as a free lance scene painter, taught me to use daylight when ever possible and to use lamps that had a daylight factor when needed, for to get the colours correct and the tonal values balanced it was bar far best in natural daylight. This was however studio practice and when the canvas was sent to the theatre it became necessary to rework, under artificial lights, the canvas because of the demands from the designer, director and lighting director, the colour balance would be completely altered by the intensity of light and the use of coloured filters, a similar result is found when paintings are hung in galleries that have artificial lighting and coloured walls or floors. The direction of the light and its subsequent reflected angle can transform colours and hues, for it needs to be remembered that ‘ a painting as few tactile attributes. It is totally dependent on surface reflectance’
The play over light over smooth or impasto surfaces alter the effect that the eye perceives and that the relining of a canvas as well as the cleaning of the same can alter the viewers appreciation of the artists intent- ‘ the conservator’s primary loyalty is to the artist’ and then the artist can influence humanity.
‘Solvent action and the degree of persistence used in the removal of oxidized layers have a profound effect on the visual values’, ‘white, for instance, is not simply a tone but a colour’ and is worth noting when we consider the painter as an individual, all painters as individuals along with the spectators and restorers, not all painters, spectators and restorers view colours with the same sense of value. The surgeon, as it where, needs to remember that the work in front of him/her is an individual work of art with their own need to expression.
The gallery as well, as the restorer, needs to consider how best to show works of art, it is important for students to see the real article and not be content with a photographic record. Travelling to school, generally took three buses each way, meant that the return would take me through the city centre of Birmingham on foot and gave me the opportunity to spend time in the city art gallery before it closed in the evening, good during the summer or on wet evenings, this offered me the chance to see painters work on a regular basis and my joy was to look at the large collection of Pre Raphaelite paintings, their intensity of colour and craftsmanship was a constant inspiration to me, it could never be the same to have seen these fine works as photographic copies, especially when you may consider that those who produce the copies have never seen the originals. This is the danger therefore when applying varnish, especially the liberally applied tinted varnish of the past, in the cleaning or restoring of a painting, the fine glaze of pigment that may have been used by the artist to change the colour or hue can be lost or altered beneath a varnish or removed by a careless worker whilst cleaning, lost or removed with such ease, sometimes without the restorer noticing, can alter the artists intention or vision.
From a restorers view point there are many aspects of aging that cannot be redeemed or altered to good effect, pigments oxidize and change colour and effect the surrounding pigment, the effect can alter the balance and depth of a picture, a fading yellow that had been mixed to form green, will now leave an area blue.
Now a final comment in this posting on my blog, the use of oil as a medium was clearly known in antiquity, mixed with pigment and used as a paint, mostly to give extended time on frescoes, the paint applied as a dry, coat, secco, used sparingly, later this was used with tempera in the same manner but the whole would be varnished in order to preserve and give the dry looking tempera a more brilliant and deep colour. This coating could also be retouched and re-varnished, a procedure that would gone on for centuries. Clearly it should not have been any great step to try and make the medium and the preservative as one coat, to dismiss the egg yolk as a base and use only the oil and varnish. There is a problem however in the chemical make up of the pigments used, they are not all equal and have structures that are very different, ranging from metals, stone and vegetable bases, chemically not stable and often light sensitive, extended periods of time and sun light are able to change and fade the colours, this and the lack of consistent development as given rise to the restorer becoming so much more of an academic, if not now a scientific post but the essential that we must remember is to pay homage to the artist, when we attempt to restore a painting and not indulge in a re interpretation.
The use of animal glue as a medium is also one that I am aware of through my time in theatre, when I first started work in London we restored sets that had been painted during the 1930s and they were painted with glue size and pigment, most of the time we used whiting as a bulk pigment and then added other colours, unlike Titanium white, whiting had very little covering power but bulked the medium. The advantages for glue size was that at the end of the play's run the canvas was laid face down and the back of the canvas was drentched with hot water and scrubbed, resulting in the whole image lifting from the canvas and leaving it fresh for a new image to be painted. Animal glue can also be used with gesso, traditional priming for most early paintings and especially for early oil painting on wooden panels, the panel would be spread with a mixture of glue and gesso, using a spatula to smooth the surface, on drying it was then pumiced down and coated with more size, this led later to the same method being used to create a copy of 'Japanese lacquer', the animal if left to boil for some time becomes very hard and brittle, can be worked over almost the same as bone and then varnished and coloured to appear as tortouse shell or Japanese decoration.