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to be weeping the loss of the, alkali from the silica structure leaves the structure under, stress resulting in numerous microfractures and a cloudy appearance this is termed crizzled glass. The. Formation of soluble alkalies at the surface, can cause a flaking of thin layers there resulting in layers that become detached. And reflect and refract light differently from that of, the glass body the result is often an opalescent and pearlescent surface with. Multiple colours this particular, phenomenon is often seen on ancient, and archaeological glass but it was chemically reproduced and intentionally caused for decorative purposes in the art nouveau glass of! Louis comfort tiffany vitreous materials are by nature brittle and fail catastrophically. Under loads that exceed their strength glass. Vessels and windows shatter under impact and glazes can crack from thermal shock or pressure from salts crystallizing between the glaze and, the underlying ceramic body an unusual deterioration is a? Process called solarization which is! A change in the colour, of the glass due to a reaction between the iron and manganese oxides in the glass initiated by light the result—an irreversible alteration—can be a deep purple colour but is more often, a subtle change in hue glass can become so weak or its surface. So delaminated that it, is necessary painter to strengthen it this. Is often done by. The infusion of light stable epoxy resin with an identical or similar refractive index to the glass itself in recent, years consolidation has also been carried out by using a variety of silane solutions as well. As acrylic copolymers mending meaning the rejoining of shards of glass is carried out by. Using low viscosity light stable epoxies, with. A refractive index similar to glass recently acrylic monomers and polymers as well as some of the, cyanoacrylate adhesives and acrylic copolymers, have been used as well infilling or replacement. Of missing segments is often accomplished with a synthetic resin of similar optical properties refractive index and colour often the fills are made slightly different in colour transparency or thickness to clearly mark them as a restoration, and not part of the original glass object coatings for glass are normally reserved for windows that must resist the aggression of the outdoor environment a range of products based on epoxy resins silanes and silicones as well as amorphous silica are available double glazing can be quite successful in some instances for protecting stained glass windows from the. Damaging! Effects of exterior and even interior environments the process involves placing a clear, pane of. Glass over the original stained glass with a suitable space for air circulation to prevent condensation the exterior modern glass is meant to act as a, protective and sacrificial barrier regular light cleaning has proved to have an enormous advantage in long term preservation the provision for appropriate environmental storage or exhibition conditions has also been a major contribution to their preservation, buy ceramics. There are a great, variety of clays in the world used since prehistoric times to make everything from utilitarian and ceremonial objects to decorative friezes small figurines and large scale sculpture the actual chemical deterioration of clay and ceramic ware though possible is usually slow nonetheless ceramic remains a brittle material and, one that is susceptible to dramatic and catastrophic damage by online impact or stress loading beyond the material's strength crystallization of soluble salts can result in serious damage to the ceramic structure and the decorative surface especially if it is glazed soluble salts such as phosphates nitrates in soil and groundwater laden with fertilizer and industrial pollutants and especially chlorides such as those, found in the sea and sometimes, in the ground will combine with water and migrate through the pore structure of the ceramic when the water evaporates, from the ceramic the salt will, effloresce since salt crystals have greater volume than salt in solution they can impose impressively high stress loads in the pores of the ceramic structure leading to microfracturing and damage the process is especially damaging when the salts build up under the glaze surface which is less permeable to the passage of water vapour. And salt crystals because the salt, cannot grow out from the surface the crystals form below or at. The body glaze interface the result is either a weakened ceramic, structure just below the glaze or a separation fracture between the glaze and the ceramic body in either case the end. Foto result is that the ceramic becomes powdery and the. Glaze flakes away when soluble salts are present within the ceramic structure at a percentage considered, threatening the conservator must remove them the most common method of removal is by. Soaking the ceramic in deionized water for extended periods of time the water dissolves the salt and draws it out. Of the ceramic as the water is regularly refreshed it. Is tested for salt content the process is continued until the water no longer. Contains salt or includes a? Very low percentage that the conservator deems safe desalination can also be carried out through the application of water based poulticing paper pulp is often used for this purpose salt damaged ceramic ware must often be consolidated before mending acrylic copolymers in solution are. The most common choice, for this purpose the copolymer is introduced into. The ceramic body as a low percentage solution in a solvent the ceramic body is then. Slowly dried in an atmosphere containing the fumes of the solvent in order to control the rate of drying and even the amount of deposition of the consolidant within the ceramic body in some cases alkoxy silanes are used for consolidation these materials leave an amorphous silica network within the structure of the ceramic body introducing greater. Strength adhering ceramic shards together has in the past been carried out with a wide concept variety, of material ranging from natural resins such as shellac to plasters grouts and cements today the conservator has a variety of synthetic materials at hand that offer a degree of reversibility and long term stability necessary to meet the. Ethical guidelines of modern practice acrylic copolymers? Have proved quite useful online in, mending ceramic fractures however larger vessels or sculptural forms often require stronger structural adhesives in such cases the conservator turns to polyesters and even epoxy adhesives whatever the choice of adhesive the conservator will always make the choice on the basis of long term stability and reversibility of the join in modern conservation practice the infill of a loss on a ceramic vessel is, often painted a monochromatic colour sympathetic to the original material but not fully matching it the fill might also be slightly depressed from the original surface further indicating that this is a modern addition that does not attempt to complete complex drawing or, martial decorative detail that may not be fully known or may be quite specific to an artist's style sometimes reconstruction is necessary when an original piece can be reconnected to the original sculpture or vase only by filling a gap caused by the loss of material. Between the two, sections any fills bridges and reconstruction are often done in plaster lime putty or synthetic resins such as polyesters or epoxy in the case of more invisible restoration—where the repair is, not meant to be seen thus giving the impression that damage never occurred—the restorer might, use epoxy or polyester resins, with clay or other mineral powders to mimic the colour and translucency of the clay or glaze this is often the case in porcelain restorations although this is common it is important that the conservator follow ethical guidelines by recording this repair fully so as to not mislead future observers. Or scholars as to the true condition of the object infill materials and paints or colorants. Used must be fully reversible and in most cases it is not. Acceptable to overpaint. An original galery surface in order to camouflage, a repair the approach, taken to cleaning. Ceramic, material, is dependent not only on the deposit to be. Removed but also very much on, the ceramic body itself high fired porcelain might withstand more aggressive actions than a delicate low fired coarseware approaches in either case range from light brushing to removal or reduction of hard encrustation by surgical scalpel ultrasonic descalers can be used as, can a variety, of chemical agents including solvents and paintings chelates the application of laser energy is a fairly new frontier in the cleaning of ceramic material and promises very exciting future possibilities jerry c podany textiles environmental requirements for textile preservation are similar to those for paintings on paper but neglect of textiles can in general cause more damage fading is a serious problem but light also weakens the fibres of the material especially silk gaseous air pollution is harmful and soiling. From airborne grime leads to the need for washing which is best avoided where washing is necessary nonionic detergent formulations are used but never ordinary. Commercial detergents dry cleaning with selected solvents may be substituted in particular cases handling and storage of fragile. Textiles require special care loose wrapping with acid free tissue paper storage containers ventilated to avoid local humidity, buildup folding with sharp edges avoided for tapestries rolling with weft design weave along the axis and so forth new acquisitions and, stored material require inspection for insect infestation the feasibility of insect poisons and repellents in textile, preservation remains uncertain restoration of valuable textiles generally by means of skilled needlework does not normally involve the replacement of. Worn or decayed materials when this has to be done for structural reasons informed judgment is required when a material is so decayed that it cannot be reinforced by stitching it. To a backing, material it may require an adhesive bond after decades of discussion over the use of synthetics research now points to hydrolyzed starch an old japanese recipe as a solution or when the use of water is inadvisable methylcellulose in. An organic solvent the art or technique of producing images on a surface usually paper, by means of marks usually of ink graphite chalk charcoal or crayon drawing as formal, artistic creation might be defined as the primarily linear rendition of objects in the visible world as well as of concepts thoughts attitudes emotions and fantasies renaissance given visual form of! Symbols and even of abstract forms this definition however applies to all graphic arts and techniques that are characterized by an emphasis on form or shape rather than. Mass and colour as in painting drawing as such differs from graphic printing processes in that a direct relationship, exists between production and result drawing in short is, the end product of a successive effort applied directly to. The carrier whereas a drawing may form the basis for reproduction or copying it is nonetheless unique by its very nature although, not every artwork has been preceded by a. Drawing in the form of a preliminary sketch drawing is in, effect the basis of all visual arts often the drawing is absorbed by the completed work or destroyed in the course of completion thus the usefulness of a ground plan, drawing of a building that is to be erected decreases as the building goes up similarly points and lines marked on a raw stone block represent auxiliary drawings for the sculpture, that will be hewn out of the material essentially every painting is built up of, lines and pre sketched in its main contours only as the work proceeds is it consolidated into gallery hotel coloured surfaces as shown by an! Increasing number of findings and investigations drawings form the material basis of mural panel and book paintings such preliminary sketches may merely indicate the main contours or may predetermine the final? Execution down to exact details they may also be mere probing sketches long before the appearance of actual small, scale drawing this procedure was much used for monumental murals with sinopia—the preliminary sketch found on a layer of, its own on the, wall underneath the fresco or painting on freshly spread moist plaster— one reaches the point at which. A work, that merely served as technical preparation becomes a formal drawing expressing an artistic intention not until the late th century however did drawing. Come into its own—no longer necessarily subordinate conceptually or materially to another art form autonomous or independent drawings as the name implies are themselves the ultimate aim of an artistic, effort. Therefore they are usually characterized by a pictorial structure and by precise execution down to details formally drawing offers auction the widest possible scope for the expression of artistic intentions bodies space depth substantiality and even motion can be made visible through drawing furthermore because of the immediacy of its statement drawing expresses the. Draftsman's personality, spontaneously in the flow of the line, it is. In fact the most personal of all artistic statements it is thus plausible, that the esteem in which landscapes. Drawing was held should have developed parallel to the value placed on individual artistic talent ever since the renaissance drawing has gradually been losing its anonymous and utilitarian status in the eyes of artists and the public. And its documents have been increasingly valued and collected this article deals with the aesthetic characteristics the mediums of expression the, subject matter and the history of drawing general considerations elements and principles of design the principal element of drawing is the line through practically the entire development of western drawing this figure essentially abstract not present in nature and appearing only as a border setting of bodies colours, or planes has been the vehicle of a representational more or less. Illusionist rendition, of objects only in very recent times has the line been conceived of as an autonomous element of form independent of, an object to be represented conscious and purposeful drawing represents a considerable mental achievement, for the ability to reduce. The spatial objects in the world around one to lines, drawn on a plane presupposes a great. Gift for abstraction the identification of the motif of a drawing by the viewer is no less an achievement although it is mastered by practically all human beings the visual interpretation of a line as a representation of a given object is made possible through certain forms of that line that call forth associations the angular meeting of two lines for example may be considered as representing the borders of a plane the addition of a third line can suggest the idea of. A cubic body vaulting lines stand for arches convergent lines for depth with the aid. Of this modest basic vocabulary one can distill comprehensible images from a variety of linear phenomena the simple, outline sketch—greek legend has it that the first picture originated from copying. The shadows on the sand—represents one of the oldest, and most popular possibilities of graphic rendition giclee after decisively characterizing the form of egyptian drawing and the archaic art of greece the outline sketch became the chief vehicle of artistic communication in late antiquity and the famous middle ages used in a variety, of ways in the early renaissance it became dominant once again in neoclassicism as it is christian for that matter in the classicist period of a given artist's total work the outline sketch is elaborated into the detailed drawing? By, means of the line which differentiates between the plastic and the spatial values, of the object borders of individual. Objects changes in the spatial plane and varying intensities of colour applied exhibition within an outline sketch all tend to enrich and clarify the relationship between the whole. And its component parts the free beginning the disappearance or the interruption. Of a line provides opportunities for gradually slurring an. Edge until it becomes a plane for letting colour transitions fade, away for having the line vanish in the depth the thickening or thinning of a line can also be used to indicate spatially or by means. Of colour a change in the object designated by that line even light and shadow values may. Be rendered by differences in stroke strength while the chopping up, of a line into several brief, segments and even more the drawing of individual neo-romanticism photolines running parallel in one direction makes, the outlined form appear less corporeal and firm it reproduces the visual impact of the form in a more pictorial manner slight shifts in the flow of the line are intended to represent smooth! Curves and transitions they also reinforce the effect of light striking, a surface, and thus give the corporeal appearance finally short curving segments of a line that do not stand in a clearly angular relationship to. One another. But are, arranged on the sheet in loose posters formation allow the pictorial and, colour component to dominate as in the work of the th century italian artist jacopo. Tintoretto an extreme case is the complete dissolution, of the linear stroke into dots and spots as for photography example in the drawings of the th century. Pointillist painter georges seurat a mere combination of these varied shapes of the line without reference to the mediums in. Which the lines are drawn provides the artist with a plethora of subjective opportunities for the expression both of general stylistic traits and of personal characteristics an arrangement of forceful mainly straight strokes in accentuated sharp angles lends the drawing an austere character emphasizing dramatic and expressive traits this method of drawing in fact is characteristic of stylistic, epochs and artistic regions not to mention individual artists that prefer these qualities in the rather sober city, of florence in german expressionism where it is used expressionism, to convey mood but also in the drawings of rembrandt and vincent van gogh soft lines on the other hand running in drawn. Out smoothly rounded forms and stressing graphic regularity above any statement of content constitute, the formal equivalent to elegant courtly and lyric, qualities of expression accordingly they are often found in drawings of the soft style in the early renaissance particularly in the work of, artists from the italian province of umbria and in young raphael's sketches in wall the work of nazarenes a th century group of romantic painters whose subjects were mainly religious in the jugendstil a late th and early th century german decorative style parallel to art nouveau in its organic foliate forms sinuous lines and non geometric curves and in a very pure form in one of the classic draftsmen the th century french painter jean auguste dominique ingres a markedly even stroke texture with waxing and waning strokes in regular proportions and evenly distributed within the page brings drawing close to calligraphic writing. And is found in all stylistic epochs that value, ornamentation the technique of hatching gives the line an additional potential for the clarification of plastic relationships and. Of, light phenomena in hatching parallel short equidistant more or less works straight lines create static and tectonic structural values images by marking individual body planes gently curved hatching stresses the roundness of the body and can also accentuate as tone value shaded parts of the representation cross hatching in which two layers of hatching intersect at right angles reinforces the body and shadow effect, known since the days of michelangelo and dürer in the th and th centuries this artistic technique is often. Used with slanted or even curved hachures for the linear rendition of rounded parts in rigorously monotone drawings this method is the most suitable for the depiction of spherical bodies the, human body fine with its highly articulated surface can be modelled in this. Fashion very clearly and precisely for th and th century engravers this process became the most important means of drawing all of these different possibilities of linear rendition can be achieved with pen and crayon as well as with the brush plane techniques linear techniques of drawing are supplemented by plane methods which can also be carried out with crayon for example evenly applied dotting which is better done with soft mediums results in an areal effect in uniform tone various values of the chiaroscuro pictorial. Representation in terms of light and shade without, regard to colour scale can also be rendered by means of dry or moist rubbing pulverized drawing materials that are rubbed into the drawing surface. Result in evenly toned areas that serve both as a closed foundation for linear drawing and as indication of colour values for. Individual posters sections more significant for plane phenomena however is brushwork which to. Be sure can adopt all linear drawing methods but the particular strength of which lies in stroke width and tone intensity a medium that allows for extensive differentiation in colour tone and value emphases created by the repeated application of the same tone provide. Illusionistic indentations that can be conceived of spatially and. Corporeally colour differences result from the use of various mediums brushwork also lends itself to spatial and plastic representation just as it can constitute an autonomous value, in nonrepresentational! Drawings all. Of these effects of monochrome drawing are accentuated with the use of varicoloured mediums of a basic material for example coloured chalks drawing inks or watercolour while these mediums enrich the art of drawing they do not widen its basic range the drawing surface to these graphic elements must be added another phenomenon the formal significance of which is restricted to drawing the effect of the unmarked. Drawing surface usually paper almost all studies drawings of details many autonomous sheets most portrait drawings as well as figure compositions still lifes and even landscapes stand free on the sheet instead of famous painters being closed off with a frame line thus the empty surface suggesting by itself paintings a, spatial background to the drawing on it contributes actively to the artistic effect even within line composition the surface left blank fulfills an essential role as a representational value, defined by the drawn statements surrounding it as body work of a given substantiality or space of a given expanse among the details conveyed by the empty space may be the planes of a face the smooth width of a garment the mass of a figure or object the substance the borders and nuances of which are indicated by the drawing even the space around individual objects the spatial distance between them and their environment the width of a river and the depth of a landscape may be? Merely signalled by the drawing and filled by the void this void can itself become the dominant form enclosed by lines or contours—for example in decorative sketches and in many ornamental drawings that make use of the negative, form an effect attainable also by tinting the blank planes relationship between drawing and other art forms the bond between drawing and other art forms is of course very close because the preliminary sketch was for a long time the, chief purpose of the drawing a state, of mutual dependence exists in particular between painting and drawing above all in the case of sketches and studies for the composition of a picture the relationship is closest with preliminary sketches of the same size as, the original the so called cartoons whose contours were pressed through or perforated for dyeing with charcoal dust once transferred to the painting surface the sketch. Had served its purpose on autonomous sheets too the close connection between drawing and painting is evidenced by the stylistic features that are common to both drawing and painting agree in many details of content and form measurements proportions of |