AcknowledgementsAbout the authorIntroductionSources and their informationStudy and interpretation of the sourcesThe original composition of the paintThe paint''s original appearance and the artist''s original intentionNotes1. Determining the intentions of painting methods and recipesInstructions for preserving the original appearance of the paintingInstructions for taking into account the limited compatibility of pigmentsInstructions for using differences in hiding power and tinting strength of the pigmentsInstructions to compensate for differences in drying timeInstructions for fast and easy paintingInstructions for taking price differences into accountInstructions for indicating light and shade and the rendering of objectsInstructions for simplying the organisation of the representationInstructions concerning the sequence of paintingInstructions concerning the division of labour within the workshopConclusion and summaryNotes2. Methods used by painters to prevent colour changes described in 16th to early 18th century sources on oil painting techniquesHistorical terminology on discolorationInstructions to prevent discoloration caused by the oil binding mediumThe oil binding medium''s tendency to turn yellowPainters'' knowledge about the discoloration of oilProblems with coarsely ground blue pigmentsUsing a binding medium that is less liable to discolourInstructions to regulate the amount of oil in the paint layerInstructions for using intermediary medium layersInstructions for mixing colours to a lighter shade or a more saturated hueDevelopments in methods to combat the discoloration of smalt oil paintMethods to combat the discoloration of paint caused by the pigment''s discolorationDiscoloration of pigmentsHistorical knowledge on the durability of pigmentsDifferences of opinion about the colourfastness of pigmentsHistorical knowledge on the conditions that caused pigments to discolourThe choice between permanent and discolouring pigmentsMethods for improving pigments in order to counter discolorationMethods for constructing the paint layer in order to counter discolorationInstructions for limiting discolouring pigments to the underpaintingDiscussion of differences in the working methods used to combat discolorationInstructions for a durable application of unstable pigments in the top paint layerInstructions to combat the discoloration caused by the mixing of incompatible pigmentsKnowledge of the incompatibility of pigmentsInstructions for using incompatible pigmentsMethods to combat discoloration caused by the increasing transparency of oil paint layersCauses for the increase in transparency of oil paint layersHistorical knowledge on the increasing transparency of oil paint layersGaining knowledge about the paint''s discolorationTransfer of and development in knowledgeWays of gaining knowledgeThe guarantee period for colourfastnessConclusion and summaryNotes3. Verdigris Glazes in Historical Oil Paintings: Recipes and TechniquesInterpretation of green glazesPainting instructions for green glazesComposition of historical verdigrisProducing verdigrisDistilled verdigrisAppreciation of verdigrisThe colourfastness of verdigrisChanging colour from blue-green to greenIncompatibility of verdigrisInstructions for glazing with verdigrisGrindingOil mediaVarnish mediaVarnishing the glaze after dryingAdding pigments to the glazeMethods of applying glazes evenlyUnderpainting for verdigris glaze paintsDiminishing use of verdigris in the 17th centuryConclusion and summaryNotes4. Indigo as a pigment in oil painting and its fading problemsIndigo as a textile dye: production and historyPreparation of natural indigo from indigo plantsIndigo dyeImport of tropical indigo in EuropeTypes of indigo pigment used in oil mediaLumps of tropical indigoIndigo from the flower of the dyer''s vatIndigo pigment from woad leavesIndigo made from blue woolIncreasing imports of tropical indigo and its growing importance as an artists'' pigmentDifferent qualities of tropical indigoRegions from which tropical indigo was importedAssessment of quality of indigo lumpsAssessment of working properties of indigo in oil mediaQuality of indigo pigment and colourfastness of indigo paintHistorical assessment of colourfastness of indigo in oil mediaRecipes for purification of tropical indigoLight-ageing tests with synthetic and natural types of indigoPure and impure indigo in easel paintingsViews on indigo''s lightfastness and painting technique"Traditional'' techniques: indigo restricted to shadow areas and under paint layers''New'' technique: indigo used in top paint layersPainting techniques for indigo in top paint layersMixtures with lead white or chalkLead white pigment particle sizeMixtures with smaltMixtures with yellow lakesBinding media and siccativesModelling of indigo draperyDifferent states of preservation of indigo paint areasComparison of paintingsEnvironmental influences on indigo''s colour preservationImpact of painting technique on indigo''s colour preservationInfluence of the binding mediumInfluence of the mixtures with lead white and chalkInfluence of the thickness of indigo paint layersInfluence of the pigment volume concentrationInfluence of the light or dark underpaint layerInfluence of the overlying varnishInfluence of the particle sizeImpact of fading of indigo on the colour harmony and the effect of spatial illusionConclusion and summaryNotes5. Discoloration or chiascuro? An interpretation of the dark areas in Raphaels'' Transfiguration of ChristViews on the chiaroscuro in the TransfigurationThe Vasari campFirst-hand observations by 18th-century authors and the mosaic copyAnton MengsEarly 19th-century viewsThe atmospheric explanationAn error by Raphael''s pupilsThe use of wrong materialsThe darker style and rilievoAfter the restoration of 1972-76The ''expressive'' chiaroscuroRilievo and the modelling in the TransfigurationRaphael''s late style and rilievoThe modelling in the lower halfPreliminary studies and 16th-century copiesPreliminary studiesSixteenth-century copiesLight as a means of expressionDivine and earthly lightsFunction of light in early 16th-century paintingPossible causes of the darkeningVasariBlack pigmentsExamination of the paint surfaceConclusion and summaryNotesAppendices.