department for preventive conservation national ... - WebSajtovi

lo ispod nivoa originalne keramike, čime se dodatno ističenjihova razlika. Ovaj način rada primorava konzervatorana veću preciznost u radu i onemogućava prikrivanjeloše izvedenih spojeva. Mnogi konzervatori praktikujuizvođenje bojenog restauriranog dela, dodavanjemzemljanih pigmenata u gips, tako da se dobije samopribližna boja keramike. Smatra se da se time razlikaizmeđu originala i restauracije čini manje uočljivom,ako eventualno dođe do oštećenja predmeta ili retuširanogsloja koji može biti nepažnjom izgreban ili počne dase ljušti zbog starenja. Međutim, ako dođe do gubljenjaboje bojenog restauriranog dela, dobijamo kompleksnijiproblem, jer se mora zameniti čitav restaurirani deo.RETUŠ. Na početku konzervatorskog tretmana trebaodlučiti na koji način će restaurirani deo biti retuširan.Površinski sloj ne treba samo da bude obojen, već trebada ostvari odgovarajuću propustljivost svetlosti, dubinu isjaj, koji su u skladu sa originalnom površinom keramike.Opšte pravilo je da je boja retuša za nijansu svetlija odoriginalne boje, jer bi tamniji retuš restaurirarnim površinamavizuelno dao utisak tamnih praznina na predmetu.Takođe, retuširane površine ne smeju biti preteranouočljive i nametljive, kada se posmatraju sa razdaljinekoja je uobičajena za posmatranje u izložbenim vitrinama,ali moraju biti lako primetne iz blizine. 14 Polaznatačka pri izradi rertuša je ustanovljavanje glavne boje pozadinepredmeta i prema njoj se zatim sve usklađuje.Površina zdele je prekrivena bojenim slojem koji je unijansama zelene i svetlo žute boje, bez pravilnosti u dekoraciji,osim na zgrafito motivima. Pošto bi bilo neprihvatljivoimitirati raspored i razlivenost boje posude, odlučenoje da se retuš izvede zelenom bojom, ujednačenogintenziteta na čitavoj površini. Odgovarajući zemljanipigmenti su prvo dodatno izmrvljeni, da bi se dobio finijiprah koji je lakše rastvorljiv. Pigmenti su zatim rastvoreniu 3% rastvoru barlepa u destilovanoj vodi. Barlep,kao akrilna disperzija, omogućava da bojeni sloj budeotporniji i da se bolje veže za površinu gipsa. Teškoća priizvođenju retuša na gipsu predstavlja tačno pronalaženjenijanse odgovarajuće boje. Boja naneta na gips posle sušenjaje uvek svetlija, a posle nanošenja konsolidantatamnija. Zato je neophodno raditi testove na pločicamaod gipsa. Dobijeni svetlo zeleni ton je za nijansu svetlijiod svih tonova zelene koji se nalaze na zdeli, a takođe jebio u skladu i sa tonovima svetlo žute. Na kraju su retuširanepovršine mekom četkom lazurno premezane konsolidantom- 5% rastvor paraloida B72 u ksilolu, čime surestaurirani delovi dobili sjaj sličan glazuri keramike.Ovim je konzervatorsko-restauratorski tretmanpredmeta bio završen.Preporuke za čuvanje i izlaganje predmetaTemperatura: 18-25 o CRelativna vlažnost: oko 50%UV zračenje: manje od 75 mikrovata po lumenuOsvetljenje: 50-250 luxSvi aero zagađivači bi trebalo da budu neutralisaniPolice u depou, kao i izložbene vitrine, trebalo bi dabudu izrađene od inertnih materijala - metala i stakla.Preporučuje se da se keramički predmeti čuvaju u vitrinamasa vratima od stakla, koja olakšavaju kontrolu iposmatranje predmeta, smanjuju razmenu vazduha i prodorzagađivača i prašine. Police moraju biti prekrivenepolietilenskom folijom, koja štiti predmet od dodira sametalom i ujedno je hemijski najbezbzedniji materijal.Izbor pristupa restauraciji i izvođenje retuša zavisidelom od konzervatora, a delom od usvojenog principarada konzervatorskog centra, pri čemu se moraju imatiu vidu i posebni zahtevi kustosa ili vlasnika. Istovremesothat restored parts get the colour and note similar topottery. Meaning, the restored part of plaster remainswhite in colour, and the difference from original surfaceof pottery is emphasized by retouching. When workingwith white plaster, aging of the retouch and its peelingmust be taken into consideration, as well as possibly necessaryre- retouching after some years.The second approach that is not commonly used, consistsof implementation of restored parts, which are alwaysvery little under level of original pottery and thusmaking their difference additionally emphasized.This requiresbetter precision of the conservator during his workand prevents hiding of badly managed joints. Many conservatorscolour the restored part by adding earth pigmentsinto plaster thus obtaining approximate colour ofpottery. It is believed to diminish the difference betweenthe original pottery and the restoration, in case the restoredpart or retouched layer are damaged by unintentionalscratching or peeling due to aging. However, if the colourof coloured restored part is lost, it is a more complex issue,since the whole restored part must be replaced.RETOUCH. At the beginning of conservation treatmentit has to be decided how the restored part will beretouched. Surface layer must not only be coloured, butit must reach adequate penetration of light, depth andshine, in accordance with the surface of original pottery.General rule is that colour of retouch should be onenuance lighter from the original colour, since the darkerretouch on restored surfaces would give impression ofdark voids on the object. Moreover, retouched surfacesmust not be too noticeable and provoking when lookedfrom distance that is common for watching display casesbut they must be easily noticeable when closely lookedat. 14 Diagnostic of main colour of object backgroundwas the outset in making retouch and according tothat everything else was adjusted.Surface of the dish was covered with coloured layerthat was in nuance of green and light yellow colour, withoutregularity of decoration, except on sgraffito motifs.Since it would be unacceptable to imitate layout andoverflow of colour of the dish, it was decided that theretouch should be green and of equal intensity on thewhole surface. Adequate earth pigments were at firstcrumbled as to get fine powder that is easily soluble.Pigments were then dissolved in 3% Barlep solvent inwater. Barlep as acrylic dispersion enables better resistanceof coloured layer and to better bond with plastersurface. Contriving the exact nuance of adequate colourrepresents difficulty during retouch implementation onthe plaster. Inflicted colour on the plaster after dryingout is always lighter and after implementation of consolidantdarker. Therefore it was necessary to perform teston the pellets of the plaster. Obtained light green notewas for nuance lighter from all notes of green colourthat were on the dish, also it was compatible with notesof light yellow. At the end retouched surfaces were azurecoated with soft brush dipped in consolidant – 5%solvent Paraloid B72 in xylol which gave to restoredparts shine similar to glazed pottery.With this conservation – restoration treatment wasdone.Recommendations for storage and exhibitingthe objectTemperature: 18-25 o CRelative humidity: 50% ±5%UV radiation: less than 75 microwatts per lumenLighting: 50-250 luxAll air contaminants should be neutralized.14 S.Buys,V.Oakley, op.cit., 140. 14 S. Buys,V. Oakley, op.cit., 140.137