Glossary

Although most of the terms below are widely agreed upon, a few have been used with different meanings in the literature. Some new terms are introduced. [1]

Application (appliqué), cast - ornamental unit in low relief, usually made in similar materials to the ground, and applied to the surface of paintings or polychrome sculptures. Often gilt or covered with tinfoil during the process of casting, before application. The term Pressbrokat (Germ.) is misleading, since the process does involves neither pressure nor stamping. To be distinguished from pastiglia. Cast appliqué brocade has apparently not been much used in Italy.

Bole - a clay (consisting of kaolinite and other clay minerals), used as a substratum for gilding and capable of receiving a high polish when burnished. Being a clay, bole consists not of roundish but of minute plate-like elements. Due to compression during the burnishing process these plates come to lie down horizontally, thus contributing considerably to the final perfection of the polished gilding.[2] Its colour is normally reddish-brown owing to a natural content of iron oxide, but yellow and other variants are also to be found.

Burnishing - the final polishing of leaf gilding, today done with an agate, formerly done with a hard stone like haematite or an animal's tooth. To be burnished, the metal leaf has to be laid by water gilding, i.e. on bole mixed with size or glair, not on an oil mordant. Burnishing can be done also when the metal leaf is laid directly on the ground (often mistaken as “white bole”), but with less gloss than if laid on bole.

Gesso - see ground.

Glaze - a transparent layer of paint over a lighter paint layer, or a metal leaf (cf. pictura translucida), allowing the substratum to shine through. A glaze usually gives a "warm" optical effect, cf. scumble.

Granulation (stippling)[3] - stamping of a gilt surface by numerous tiny points, rings, x-shapes or clustered points (see rosetta) into a texture with the purpose to "sparkle like millet grains", according to Cennini. Two main techniques of granulation (stippling) were employed, "all-over stamping" (granare a disteso) and "stamping in relief" (granare a rilievo). Usage in commission documents suggests that the term “granare” in the Trecento meant punch work, and probably gold tooling in general. See also rotella.

Ground - the priming or preparation of a painting, in the middle ages usually consisting of a white inert like gypsum (in southern Europe) or chalk (in the north), mixed with animal glue. The gypsum ground (gesso) in Italian painting is composed of two or more main layers of somewhat different composition and consistency {gesso grosso and gesso sottile.[4]

Incision - a) tooling of linear freehand patterns in a gilt and burnished surface with a stylus (see indentation). - b) preparatory incision in the ground of parts of the composition, prior to gilding and painting, in order to retain the design throughout the subsequent processes of execution.

Indent (incise, score, "scribe")[5], – indentation, tooling of linear freehand patterns in a gilt and burnished surface with a stylus. The process involves compression of matter, not removal, as implied by the term "engraving".

Mordant - adhesive for gold leaf, applied with a brush and often used for gilded linear patterns on draperies. A mordant consists usually of pigment in an oil-resin medium. Mordant gilding is not burnished.

Oro di metà - literally "halfway gold", term known from Trecento and Quattrocento sources as a cheaper substitute for gold leaf. Not an alloy as previously thought, but the laminate consisting of a silver base with a thin gold layer on top, used elsewhere in Europe as Zwischgold, Twistgold, gedeelt Gold etc (Germ.); partijtgoud (Dutch); and or parti (Fr.). Parallel term argentum superauratum. The English term “part gold” has recently been proposed.[6]

Pastiglia - raised ornament made directly upon the ground by applying the still warm, liquid gesso sottile with a brush and building up the relief. Subsequent gilding and burnishing of the flat ground and pastiglia took place simultaneously. The distinction from cast application follows from the difference in procedure.[7] Cennini does not use particular terms for either of the two techniques, but the established usage for their distinction is followed here.[8]

Pictura translucida -  the painting of an entire picture with transparent colours upon a substratum of tin foil (Theophilus, Chapter XXVII) which gives an effect similar to a picture in enamel. The term is by some writers today used for the local or partial glazing upon metal foil in painting and polychromy (= Germ. Lüstertechnik), see glaze.

Pouncing - a) = spolvero, the transfer of a design by rubbing a bag filled with charcoal dust or coloured powder against a perforated drawing (pounce cartoon) that has been placed upon the surface to be painted (cf. stencil). By some writers confused with the process of punching.[9] - b) the preparation of parchment with pumice and rosin (derived from pumex). Not used in this meaning here.

Punching (punch work) - tooling of the gold by the impression or stamping of patterns by means of a tool (punch), the tip of which is shaped with a figure or motif. For a particular type of tool, see rosetta. (For the styles of simple, combined, re-worked, and composite punch work, see Skaug 1994, Chapter 3.3.ii.c and Fig. 94). The technique as such is universal, and by no means  restricted to the art of painting. By some writers confused with the process of incising.[10]

Raised ornament - low relief on the surface of paintings made by either application or pastiglia.

Ritagliare - "mark out", "cut in" (Thompson 1933, p. 81, n. 1), "tidy up the outlines again", procedure preliminary to painting figures adjacent to gilt surfaces: where the gold leaf would undercut the areas to be painted, the outlines of the figures were first marked out with lead white in size. The term has by some editors of Cennini been confused with incision.[11]

Rosetta - small punch giving a cluster of minute dots, used for doing the granulation. In the following Cennini's original term has been reserved for this particular type of tool, whereas the general term "rosette" is employed for the numerous larger motif punches (penta-rosettes, hexa-rosettes, etc).

Rotella - a cog-wheel fixed to a handle, producing a stippled line or a multi-dot line when rolled over the surface. An alternative and time-saving way of producing the granulation (granare a disteso), usually giving a stripe-like texture instead of the directionally neutral texture obtained by single points from a stylus or a tiny ring punch.

Scumble - a thin, semi-opaque layer of white or light paint over a darker paint layer, barely allowing the sub­stratum to shine through. A scumble usually gives a "cold" optical effect, cf. glaze.

Sgraffito - two-coloured patterns made by scraping away the upper layer (paint) and uncovering the substratum (gold, silver, sometimes tin leaf). The technique as such is universal, its use in Romanesque stained glass windows may have been the immediate precursor for its use in panel painting.[12] In painting, the term is known since Vasari. Known in other crafts under related terms, like sgrqffiato in pottery.[13]

Shell gold – powdered gold, mixed with a medium like a pigment and applied with the brush.

Sphragiology, and respectively, sphiagiography - terms introduced in Skaug 1994 for the description and study of stamped elements in general, regardless of material and type of object (cf. the existing term "sphragistics" for the particular study of seals).

Stencil - a sheet of paper or a similar material with a cut-out motif in the negative, allowing the motif to be transferred by holding the s. firmly against a surface and jogging paint through it with a brush or a sponge. To be distinguished from pouncing, by which only the stippled outlines of a motif is transferred, needing to be completed by freehand painting.[14]

Stippling - see granulation.

Stylus (style) - a metal point, usually with a finely rounded or blunt point and not a cutting point, for making lightly ruled lines and freehand patterns in a gilt surface, cf. incision and indent.

Tooling (gold tooling) - common term for techniques of working a gilt surface in pictures, see granulation; freehand incision; punching; and indent.

Verre églomisé - glass with gold leaf attached to its back, into which drawings are scratched with a needle in the manner of pen-drawing and backed with oil colours. In spite of its modern name, the technique derives from antiquity.[15]

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Notes

[1] Jo Kirby kindly read the first draft for this glossary (publ. in Skaug 1994) and made useful suggestions. For further technical terms used in early Italian and medieval painting, see, e.g., Gettens and Stout 1942; Borsook 1980, pp. 133-135; Bomford et al. 1989, pp. 207-209; and Massing (ed.) 2003, pp. 232-235.

[2] On the plate-like crystal structure of clays and their properties in general see Mora et al. 1984, pp. 35-38.

[3] Both terms are presently in use. “Granulation" is adapted directly from the Trecento term granare (cf. Battaglia VI, 1961, p. 1033), but see discussion in Skaug 1994, Chapter 3.3.ii.b. "Graining" (Thompson 1936, pp. 68 ff) can be confused with the painted imitation of wooden grain.

[4] Gesso being the Italian term for gypsum, there seems to be no advantage in applying the term generally to any ground regardless of material (cf. Gettens and Stout 1942, p. 233; and Newbery et al. 1990, p. 180), with the consequence that authors have to introduce explanatory constructions like the chemically impossible "chalk gesso" and the pleonastic "gypsym gesso".

[5] The term “scribe” was proposed by Polzer 1981, p. 577, in order to avoid confusion with engraving and quite different techniques in medieval painting and polychromy. Straub 1984, p. 169, suggests the term trassieren for the same necessary distinction.

[6] The term is used in Cennini, Chapter LXXXXV (Thompson 1932, p. 59); in the Florentine painters’ statutes of 135 and the Sienese of 1355; and in Neri di Bicci’s diary 1453-75 (Santi 1976, pp. 38 ff). The parallel term argentum superauratum occurs in the Perugian statutes of 1366 (kindly communicated by Jo Kirby). The common translation of oro di metà as an alloy, first suggested by Merrifield 1844 (T. 1933, p. 60 and most other editions) is erroneous. Etymological and technical evidence clearly indicate the laminated silver-gold foil mentioned above, see Flemestad and Skaug 1981 (UO Årbok); Skaug 1981 (NKF); and especially idem 1993. For “part gold” and former English terms, see Nadolny (1999), 2003, p. 186, n. 55.

[7] In the catalogue Palazzo Davanzati (Engl. ed., M. F. Todorow, Florence 1986, pp. 20 and 46), the term pastiglia is used for cast applications. Frinta 1981 uses pastiglia both for freehand and cast relief, and in idem 1985/88 the term further loses precision by also comprising stamping. Norton et al. 1987 repeat Frinta's usage of 1981, pp. 14 ff (n. 13), 25 ff, and Figs. 27-34. Newbery et al. 1990, p. 109, use pastiglia as a general term, and then have to explain whether the "pastiglia" has been "brushed" (pp. 85, 97, 98) or "cast", "pressed", or "applied" (pp. 45, 90, 91, 95).

[8] Cennini/Thompson 1933, p.73, n. 1, “Modeling […] with gesso applied with a brush is now generally called pastiglia”, see also Mayer 1973, p. 282. Distinction between pastiglia and cast application has been consistent in current technical literature, see e.g. Straub 1984, pp. 170 ff and 173 ff, and Tångeberg 1987, p. 61. For murals the term is used in the same way, comprising also wax, see Borsook 1980 (1960), Fig. 4 (p. 25) and Glossary p. 134 (repeated in Borsook and Superbi Gioffredi 1986, p. 133). Serck-Dewaide 1990 does not use the Italian term pastiglia when dealing with Central and North European material, but agrees on its specific meaning above (personal communication). The terminological variant "pastiglio" (Hills 1990, pp. 108 ff et passim) is unknown elsewhere and must be a misunderstanding

[9] Offner and Steinweg 1965, p. 86, n. 11 and pp, 127, 133; Hendy 1974, pp. 87 ff.

[10] Hendy 1974, p. 90, for incised rays in gilding; Mora and Philippot 1984, p. 143, for preparatory incised drawing in mural paintings.

[11] By Herringham 1899, p. 95, as “indent”. Brunello 1971, p. 7, n. 5, explains ritagliare as “segnare i contorni d’una figura per mezzo di un ferro appuntito". To do or redo the incision, however, is clearly not what Cennini speaks about in Chapter CXL (= "ritagliare con biacca e pennello", cf. Thompson 1932, p. 83, and idem 1933, p. 86). The procedure has been confirmed by technical examination in Nikolaus 1973 and Muller 1978, see Chapter 3.1. below.

[12] See Theophilus, Second Book, Chapter 21 (Hawthorne and Smith 1979, p. 64 and Plates II-III).

[13] The difference in terminology between painting and pottery was noticed by G. Baldwin Brown, see Maclehouse-Brown 1907, pp. 243-244, n. 1. Cennini does not use a particular term, but in painting the term sgraffito has been consistent since Vasari's time, see Vasari/Bettarini 1966,1, pp. 142-143. For modern technical literature see Thompson 1936, p. 71; Straub 1984, pp. 229 ff; Muller 1985/88; and Bomford et al. 1989, p. 208. The introduction of the term graffiato also for painting (Hills 1987, pp. 109-112) is based on the erroneous assumption that, during the Trecento, the technique was adapted from oriental pottery to painting.

[14] The processes as well as terms of stencilling vs. pouncing are widely agreed upon as defined above, including the Technical Glossary in Mora and Philippot 1984, p. 326. In the text, however, the unusual term “pouncing stencil” is used for a pounce cartoon (pp. 144, 152, and Plate 101).

[15] The French frame-maker Jean-Baptiste Glomy (d. 1786) used the technique for his glass mounts (“glomyised glass”).