【Method & Material】十四至十六世纪欧洲绘画技法及材料之一：架上绘画之支撑物

整理者按：Support（支撑体）是所有绘画的颜料层所依赖的最底层，十四至十六世纪，前期画家们都推崇木质的支撑体通过打磨可以达到的光滑感，一方面因为中世纪喜欢用镀金来装饰或者作为背景，需要极其光滑以及相对柔软的表面，好让金片能服帖地平铺在底层上。另一方面因为当时的蛋彩不能在画的时候调色，必须事先调好，又因为每种颜色所盖及的区域会相对的小（中世纪的画师Ceninno推荐画家在一种颜色的过渡中起码分出三个色度），所以画家所用的画笔都很细小，因此也不适合帆布那种相对粗的质地。再者，就算是逐渐开始利用帆布大家准备工作和很多技法的运用都还是慢慢从木质支撑的方法过渡到完全通过油彩和帆布来发展出大量的全新的技法。Panel Construction Material: white poplar or black poplar, walnut and lime as occasional alternative (Italy), oak used by Netherlands, France and England, and a variety of timbers not only due to the availability of the woods but also the trading with Baltic regions (Southern Germany: limewoods, Northern Germany and Netherlands oak)Property: • Poplar: fast-growing, soft, weak with open cells, easily shrinking and swelling, prone to infestation by beetles and due to humidity• Oak: hard and slow-growing and thus not vulnerable to all natural changesUse/making: due to deforestation and over-grazing and thus a chronic shortage of timber• Cutting or division of a log into planks means that only the cut across the diameter of the log (quarter sawn) is relatively stable and that other tangentially sawn planks are prone to warping due their asymmetry of the growth rings. • The fact that the wood panel is usually painted on one side creates a repeated cycles of high and low humidity on the unprotected back and thus more shrinkage and permanent warp.• Past restoration to flatten the panels with pressure and moisture leads to splits and cracks.• The planks need to be seasoned to be moderately dry so that it can be used and yet not too lack of moisture to stay in stable shape (shrink, warping, cracking, splitting)• Small planks will be butt-joined by casein glue made from milk cheese or skins, bones and other animal wastes (goat-skin glue), and reinforced by dowel, wooden plates pegged and wooden butterflies. • Wide plank can avoid joints from splitting open, but risks major flaws such as knot and erratic grains due to the branches, which is sometimes corrected by inserting other pieces.• On the backs, (usually for Italian panels only)cross-battens were attached to strengthen the large panels and prevent warping, using long nails hammered through from the back or from the front.• Altarpieces are not only pieced together by planks but also constructed and painted in separate sections but come together on the altarblock as a unified whole. Predella and uppter tiers, however, are mentioned separately.• The carpentry in frames and joining involved is usually made by specialist wood-worker and considered as the property of the patron, though occasionally painters do supply the wood. In Northern Europe, the panel woodwork is more esteemed for craftsmanship.• Frames are constructed in different ways for larger panels. In Venice, frames are not made according to the paintings but as separate sections are richly decorated and later fitted, whereas in Tuscany, frames for altarpieces are integral to the panels to support the whole. The horizontal and vertical mouldings were not always constructed in a single whole. For the smaller panels (including round panels called tondi), most frames were built-in and gilding for the frame and the image is done in a single process.• Decoration (tabernacle) and particularly pastiglia is usually sympathetic to the architectural setting of the painting. Gilding is usually used for contrasting effect against the painting background, blue or ultramarine.• The altarpieces in Northern Europe is usually carved in on e piece of frame and painting surface from the plank of wood “Engaged” frame, which are fitted round the panel and pegged and glued together at the corner is also employed, mainly due to the decoration of the frame on both side of the panel. Painting the reversed suface increases its stability and reduced any tendency of the wood to absord or lose moisture and thus to warp or crack.• The separate construction of the frame can usually be identified by the fact that gesso ground extends beneath the area of the frame. And vice versa.• Later practices in 15th century put much less emphasis on the decorative effect of the frame and thus most of the frames were constructed separately. But the frame and panel construction were still consulted closely between painting and woodcarvers.Panels of learnt examples, conditions and causes:Duccio, The Annunciation in Maesta in Siena Cathedral Annunciation is a panel within the altarpiece Maesta in Siena. It belongs to a wide horizontal plank of poplar which forms the front predella. Due a series of dismemberment, its thickness is thinned down to about half of the original. A prominent horizontal grain is present and caused structural splits across the upper centre where the paint was lost, and a knot, resulting in paint flakes.The dismemberment also destroyed the original frame and the linen and gesso layer was cut through. In this case, the analysis of the panel could give more speculation on how the whole altarpiece is constructed, supported and placed in the original context.Canvas paintingsMaterial: silk, linenCanvas didn’t have as much popularity as panel and most were not intended to be permanent objects only for theatrical events or processions. The use of canvas derives from the need for light weight support for banners. Around mid-15th century, the trend in Netherlandish paintings to use canvas influenced firstly the north-east Italian painters to adopted canvas for works originally intended on canvas. Venetian painter adopted canvas due to the damp environment that is hostile to both fresco and panels. For double-sided constructions, the canvas was stretched on a temporary stretcher and then pinned over a wooden support. Painted borders are used as indication for relining.