Giotto's Technique

The paintings of the 13th and 14th centuries show a significant continuity in the use of materials and techniques. Wooden support, preparation with plaster and glue, tempera painting, gilding. Written towards the end of the 14th century, the art book by Cennino Cennini still remains today the primary source for the knowledge of the ways of proceeding of the 14th century painters. Cennini teaches the way of those who know art, the choice of wood, how to glue the various boards, how to treat them and prepare them for painting with seven, eight coats of plaster and glue until they are reduced to the whiteness and smoothness of ivory. Great importance is given to the stage of the preparatory drawing, which is usually made separately and then reported on the support according to one of the many traditional techniques. The composition was outlined with willow charcoal, hiding folds and faces, then the table was dusted and the drawing perfected by passing it over with clear water and a few drops of ink. The figure is now enriched with a light watercolor shading. Once the drawing is completed on the gessoed and glued surface, the outlines of the figures are cut with a punch mark, dividing the areas that must be gilded from those that are going to be painted with tempera. At this point, the bowl dissolved with a water-based binder is applied with a smooth and flat brush all over the surface that is to be gilded, taking care to keep an even thickness of the layers without stopping the brush. This operation must be repeated, always according to the instructions of Cennino Cennini, four more times, using a glue that is thicker and thicker. When the surface has been made smooth by a linen cloth, it is then possible to apply the gold leaf. After laying down the gold leaf on the gilding doll, it is then cut with an appropriate knife to reduce it to the size needed. Then it is possible to take hold of the foil, exploiting the static electricity of the brush. Having wet the area to gild with beaten egg white diluted with water, the gold leaf is delicately applied to the surface. This operation is repeated until the desired surface is completely covered, and then the gold leaf is gently pressed with a piece of cotton wool. When the gilding operation is finished and the surface is burnished, and if necessary, enriched with punch marks for further paintings. On the golden surface, on the hallows, and on the backgrounds, decorative interventions are carried out through incisions, or even using a series of punches capable of imprinting small decorative motifs on the surface, which are repeated according to a pre-arranged pattern. The colors, prepared in small containers in shades from dark to light, are always tempered with egg yolk and spread with juxtaposition and fusion. At this point, we move on to the coloring the table, starting preferably, as Cennini recommends, from the clothes of the characters and the architecture, or in any case from the background elements. The drafting of the skin tones according to the rules of the 14th century treaty requires a base of green color obtained with green earth and white lead that can reveal the underlying chiaroscuro design. It is then given, on the cheeks and lips, a pink color composed of cinnabar and white lead. We now proceed reinforcing the drawing with the verdaccio. The flesh color is obtained by starting the drafting with the hatching technique, this time from light to dark, blending the already prepared shades, letting always shine through a little the green that is below. we now proceed reinforcing the drawing with the hatching technique, letting always shine through a little the green that is below. But we have already drawn the character's name and the character's family name. E abbi che la tavola richiede essere più volte campeggiata che in muro, ma non però tanto che io non voglia che il verde che è sotto le incarnazioni sempre un poco traspaia. Quando hai ridotto le tue incarnazioni che il viso stia appresso di bene, fa un'incarnazione più chiaretta e va ricercando su per gli dossi del viso, biancheggiando a poco a poco con delicato modo, perfino a tanto che pervegna con biacca pura toccare sopra alcuno rilevuzzo più in fuora che gli altri come sarebbe sopra le ciglia o sopra la punta del naso. Poi profila gli occhi di sopra un profiluzzo di black con alcuno peluzzo, com'i sta all'occhio, e le nari del naso. Poi togli un poco di sinopia scura con un miccino di nero e profila ogni estremità di naso, d'occhi, di ciglia, di capellature, di mani, di pie e generalmente d'ogni cosa come in muro ti mostrai, sempre con la detta tempera di rossume d'uovo. Small highlights or gilded decorations on paintings in the background can be obtained by gilding evenly the surface interested, applying the color on it, and then searching the gold underneath the painting in the background by softly scratching the surface according to the prearranged drawing. The mordant is applied with a brush to the areas that are to be gilded. On these areas is then laid and lightly pressed the gold leaf, soon after the adhesive has become tacky. The excess gold leaf is then easily brushed away. If very small decorative elements must be gilded, it is possible to finely grind pieces of gold leaf and mix them with a binder, usually Arabic gum, using then a brush to paint the gold color. This is the so called gold dust gilding that takes the name after the recipient, a shell that was once used for this preparation.