Unqualified terms describe medieval and Renaissance practices (for CV purposes the Middle Ages ends in 1480), but in other cases historical qualifiers are in parentheses:
R Renaissance (Early Modern)
PM post-medieval (indeterminate, i.e., c. 1480 onward)
mod modern (19th and 20th centuries)
rest used in restoration (e.g., repair leads)
To remove selected areas of the surface of the glass with a stone or iron point, file, wheel, or bit; the colored layer of FLASHED GLASS, notably red, was often selectively removed to reveal colorless glass; the abraded area was sometimes then SILVER STAINED (cf. ACID ETCHING).
An external product, such as dirt or putty, adventitiously adhered to the surface of the glass (cf. FALSE PATINA; CORROSION CRUST).
acid etching (PM)
To selectively remove the colored layer of glass from FLASHED GLASS by the application of an acid (cf. ABRASION). This technique seems to have been used in an area centered on south Germany from the late 15th to 16th centuries, but afterwards it was not widely practiced until the 19th century.
antique glass (rest)
Blown glasses manufactured, especially in the 19th century, to resemble medieval ones.
A small piece of glass, usually representing a jewel, affixed to the surface of a piece of glass of a different color with PAINT, which was applied round the edges of this appliqué and then fired (cf. INSERTION). The technique is described by Theophilus, and known in a few 12th– and 13th-century examples.
An iron framework set into a window opening to support panels of stained glass. The panels were held in place by wedge-shaped keys that passed through lugs (protruding ‘handles’) on the armature (cf. SADDLE-BAR). (mod) The armature may be made of a non-corroding alloy, especially when protective glazing is installed. The bars may have a T-shaped profile to accommodate the panels, hence the term T-bars. In 12th– and 13th-century installations, the iron bars were usually attached to a wooden frame recessed (in a glazing groove) in the stonework, but later they might pass through thin mullions, or directly into the stone window molding.
Corrosion occurring on the side of the glass opposite to the PAINT, but in a pattern that mirrors the painted design. Study has indicated that it is limited to areas where the original glass painter has applied BACK-PAINTING (cf. GHOST IMAGE).
Painting on the back or outer surface of the glass. This is usually MATTING, either to strengthen the painted design on the inner side, or to provide a decorative pattern such as a textile design that supplements folds painted on the inner surface.
A method of enlivening shading by spreading and texturing the paint after it has been applied to the glass, using a dry brush traditionally made from the hair of a badger. Because badger hairs have forked ends, the badger blender has a firm base with a light and flexible tip. Dragged over a moist paint surface, it created soft highlights. Normally used on MATTED areas, it could be used at any stage of the painting, including after the TRACE (cf. STIPPLING).
A window composition in which horizontal bands of full-colored glass (usually figural) alternate with bands of GRISAILLE ornament (cf. CANOPY WINDOW).
A unit of architecture, defined by the vaulting system, in which there may be windows.
An unpainted decorative design, usually uncolored, formed by the lead-lines alone (cf. GRISAILLE).
A long, hollow metal pipe used to inflate molten glass. (mod)
bull’s eye glass
The center of a sheet of CROWN GLASS containing a PONTIL MARK, often of colorless glass, often used un unpainted as a surround to e.g., heraldry in late-medieval German windows (cf. QUARRIES, the English and French equivalent).
came: see lead came
An architectonic frame, executed in stained glass, for a figure or scene. This usually has columnar supports to both sides and an elaborate structure above. The style of the fictive architecture usually corresponds to the period style of the real architecture. Canopies (13th–17th centuries) are characterized by the depiction of pinnacles, turrets, gables with crockets and finials, niches and windows, vaults with hanging bosses, ogee arches, etc.
A window composition in which figures form horizontal bands, with canopies above them. When the figures are in full-color and the canopies in colorless glass with silver stain, the effect is similar to the 13th–14th century BAND WINDOW.
A full-size drawing for a window or panel. Generally, the lead lines and the details to be painted were indicated on the cartoon. The earliest cartoons were drawn on whitewashed boards or tabletops, which have been called SETTING TABLES by analogy with architectural practice; linen provided a portable alternative. Parchment could have been used for small design motifs, such as the repeat in a border. Paper was more frequently used in the later Middle Ages, as attested to in 15th-century York wills. A cartoon might be used as a working pattern throughout the production of a window, but this was not the case with the preserved 17th-century cartoons for the Cathedral of Brussels.
cement: see putty
A small piece of glass inserted into a hole abraded through a piece of glass of a different color. M & R insertions are held in place with a LEAD. An alternative method, used at least since the 16th century, was to apply PAINT in the cracks between the insertion and the base glass before firing (cf. APPLIQUÉ).
A window opening with five lobes, usually at the head of a 14th/15th-century LIGHT, or possible in a 13th-century TRACERY.
Any paint which was not fired. Cold paints were used to color very small details for which it was not expedient to cut a separate piece of glass, to fill in areas of vitreous paint which did not fire correctly, and to color significant portions of a roundel before the wide-spread use of more permanent ENAMELS.
cold overpaint (rest)
Cold paints were frequently used to restore lost paint.
copper foil; copper foiling
(mod) A technique of joining pieces of glass in a stained-glass panel, in which thin strips of copper are wrapped around the edges of the pieces of glass which are then joined together by applying SOLDER to the exposed upper and lower surfaces of the copper foil. This technique was used extensively in the creation of stained-glass windows in the USA in the late 19th and early 20th centuries. (rest) It has also been used in the restoration of older stained glass, especially before the invention of suitable adhesives for joining lass. Because copper foil is much thinner than a REPAIR LEAD, broken pieces of glass can be held much closer together in a copper-foil repair, and the broken edges of the glass do not have to be GROZED to accommodate the repair lead.
Streaks in glass, usually in a wavy pattern and slightly raised. They result from inhomogeneities in the glass composition, due to insufficient melting or mixing, and are common in medieval glasses (cf. REAMY GLASS).
Chemical deterioration of the glass; this normally results in IRIDESCENCE, EFFLORESCENCE, PITTING or CRUST formation that are visible on either or both surfaces. The type and rate of deterioration are influenced by many factors, the most crucial being the composition of the glass, and its environment. Within a stained-glass panel, one piece of glass may corrode more than another due to its differing composition. Corrosion may also appear along lines of inhomogeneity in the glass, or along scratch lines. The presence of PAINT and SILVER STAIN also has an effect on the distribution of the corrosion, which may occur either where the glass is or where it is not painted or stained. An additional corrosion phenomenon is BACK-MATCHING.
Clipping off part of the original design, especially along the edges of a composition.
Modeling by means of separate lines laid at right angles to each other.
Blown glass transferred to a PONTIL and spun into a circular sheet. A completed crown has a thick center, called a boss, bullion, or BULL’S EYE, with a rough circular mark from where it was attached to the PONTIL. Even when the pontil mark is not included in the cut piece, crown glass can often be identified by the concentric curved ridges or the curved lines along which the bubbles contained in it were elongated by the spinning process.
crust (corrosion crust)
A thick deposit of corrosion products on the surface of a glass. These crusts may render the glass opaque, and they may form on one or both surfaces. Some have a tendency to shale off, others are very hard (cf. ACCRETION; FALSE PATINA).
A tracing of lead-lines from the CARTOON which acts as a pattern for the cutting of individual pieces of glass.
cylinder glass (old term: muff glass)
Glass made by blowing a gathering of molten glass into a cylindrical shape, which was then split longitudinally and flattened. Cylinder glass can sometimes be identified by the elongation and parallel alignment of the bubbles contained in it, a pattern which is a response to the process of blowing. Early cylinder glass may also exhibit a dull side—corresponding to the side which touched the kiln surface, and a glossy side—corresponding to the upper surface in the kiln (cf. CROWN GLASS).
A small-scale preparatory sketch for a window (cf. MODEL; VIDIMUS).
A flat lead strip applied across the inner and/or outer surface(s) of a piece of glass to create the effect of a BLANK-GLAZED design. (rest) Also used to support a break. They can be applied with the glass in situ, and appear to have been especially popular prior to the 19th century.
edge-bond; edge-bonding (rest)
A method of mending breaks in glass, normally with an adhesive. While in the past, glues made from a natural proteinaceous substance derived from an animal or fish were sometimes used to bond glass, in general, repairs were made with lead until the development of water-proof synthetic adhesives in recent years. In condition descriptions, the type of adhesive used in recent restorations should be specified if the information is available (acrylic, silicone, epoxy).
A “bloom” on the surface of the glass, either naturally occurring as a result of the evaporation of solutions of glass decomposition, (rest) or the result of chemical cleaning of the glass (cf. also IRIDESCENCE).
Vitreous colorant fired on the glass. Enamels is a vitreous material consisting of a base of ground glass colored with metallic oxide(s) and suspended in an organic medium for application to the glass; it could be spread like a paint. Upon firing, the medium burned off, and the enamel fused with the glass substrate. While enamels had been applied to glass vessels since ancient times, and were used on a group of Venetian beakers that date from c. 1300, they were not commonly used on window glass until the 16th century, though there are a few known examples in Austria and Germany from the early 15th century.
false patina (rest)
An application on the outer surface of a substance intended to blend with adjacent panels that have a natural CRUST. It was sometimes applied to M/R glass, though more commonly denotes modern pieces or panels. A favorite mixture was lime and putty, sometimes fired on.
A narrow strip of glass delineating a compositional unit. (mod) The outer edging of a panel is referred to as a “breaking fillet” because glaziers anticipate that it is expendable if the putty is too hard to take the panel out without breakage.
Glass with more than one color, usually an uncolored core with a surface layer of red. Occasionally, two thin layers of colored glass surround the colorless glass layer.
A corroded image on a piece of glass that reflects the design painted on another piece and which resulted from stacking in the kiln. This was caused by the volatilization of alkali from the paint on another piece of glass, perhaps from the same panel or window, when both were fired, one onto of the other, in the same kiln. The volatilized alkali rendered the glass stacked above less durable and, therefore, more susceptible to corrosion. This phenomenon is most often seen in grisaille ornament, which was perhaps more likely to be mass-produced (cf. BACK-MATCHING, CORROSION; PALIMPEST).
A window or panel of ornamental (geometric or floral) designs, composed almost exclusively of uncolored glass, in which the designs are created by the leads alone (BLANK-GLAZING), or with the addition of PAINT and SILVER STAIN.
A method of shaping a piece of glass by using a grozing iron or a notched iron bar to nibble the edges of the glass.
Modeling by means of separate parallel lines (cf. CROSS-HATCHING).
Use of a paint to fill gaps in the design. In contemporary conservation practice, inpainting is restricted to painting within the boundaries of a fill which has been added to replace a loss. The fill and paint are preferably reversible. Early modern restorers often filled in lost detail, such as paint that was lost when the glass splintered or shaled off, or thick trace that disappeared (such as the pupil of an eye, or part of a letter) by painting directly on the original glass.
A small piece of glass inserted into a hole abraded through a piece of glass of a different color. M & R insertions are held in place with a LEAD. An alternative method, used at least since the 16th century, was to apply PAINT in the cracks between the insertion and the base glass before firing (cf. APPLIQUÉ; CHEF D’OEUVRE).
Variegated colors, giving a rainbow-like effect, on the surface of some glasses, produced by the interference of light by multiple layers of silica-rich glass CORROSION products. (rest) May result from the use of acid to remove corrosion products.
lead; lead came (older English: calm/calme)
A strip of lead, H-shaped in section, used to hold the edges of pieces of glass to form a panel. The crossbar for the “H,” which separates the two flanges, is called the heart of the lead. SOLDER was used to join the leads after wrapping them around the glass. The lead used to make cames may contain small quantities of other materials, such as antimony, silver, or copper. The presence of tin, especially in 19th-century cames, may sometimes have been due to melting down old leads, with solder adhering, to make new ones. On the whole, medieval leads have been found more resistant to deterioration than modern ones. From the 12th–16th century, lead cames were cast. On early medieval leads, the inner surface was usually trimmed to beveled edges. (R & mod) Beginning c. 1500, cames were often extruded from a mill, which leaves a visible pattern on the heart. Modern cames are most often extruded.
A window opening bounded by stonework (cf. TRACERY).
An evenly applied layer of PAINT, usually provided a half-tone shading.
Small-scale drawing of a single element, such as a figure, that could be incorporated into a variety of compositions. Existing M & R model-books attest to the use of such drawings by designers working for a variety of media.
A vertical stone shaft dividing a window into individual LIGHTS.
Same as STICKWORK but resulting in much finer lines, as if a needle were used.
overpaint; overpainting (rest)
An application of COLD or vitreous PAINT to strengthen an original design, especially where paint has been lost, or is embedded in corrosion layers. Early modern restorers used this practice rather freely (cf. INPAINT).
The paint used on glass in all periods was normally vitreous: it consisted of a mixture of finely ground glass, iron or copper oxide, and flux, applied to the glass with a brush and fired. The medium, which fired off in the kiln, was described in medieval texts as vinegar or urine, and later as oil (cf. COLD PAINT).
Old glass, painted with a new design. The term is taken from codicology of manuscripts: parchment that has one text scraped off in order to write a new one (cf. OVERPAINTING). A piece of M/R glass (usually of the period of the panel in question) that has been wiped clean of its original paint, usually by acid, and repainted with another design, either to restore a missing piece, or to fabricate an entire panel.
A unit of stained glass leaded together and designed to fit an opening in the ARMATURE or TRACERY; it may be of any shape, but rarely exceeds about one meter (40 in.) in any dimension.
Cavities which form in glass, most often on the outer surface, due to CORROSION. Spherical cavities may coalesce to form irregular shapes, and may eventually pass right through the glass. Although corrosion products usually form in the pits, so that they appear as dark or opaque dots, cleaning reverses this effect, so the dots appear lighter than the surround.
A glassblower’s tool in the form of a metal rod.
Glass which is colored throughout by metallic oxides in the glass composition (cf. FLASHED or ENAMELED glasses).
A compound applied beneath the edges of the LEADS to waterproof a stained-glass PANEL and around its circumference between the lead and the ARMATURE to waterproof a window. Putties usually contain whiting (crushed limestone) and linseed oil. Medieval compositions included cow dung and cow hair.
quarry (older English: quarrel)
A small pane of glass, usually diamond shaped (rhomboid), or a canted square, normally uncolored with a SILVER-STAINED and PAINTED decorative motif in the center. The predominant kind of GRISAILLE in the 15th century.
A four-lobed decorative motif, whether painted, leaded, or a PANEL form (cf. TREFOIL; CINQUEFOIL).
A typical medieval glass, with an undulating surface, often with slightly raised wavy patterns that are discernible to the touch and in a raking light (cf. CORD; ANTIQUED GLASS).
Replacement of LEADS.
A LEAD CAME inserted into a break and SOLDERED to the existing lead matrix to hold broken pieces of glass in place. Often the edges of the broken glass had to be GROZED to accommodate the heart of the lead (cf. DUTCHMAN; EDGE-BONDED).
A nearly exact duplicate. In the case of roundels, replicas may be of the same period (cf. VARIANT; VERSION).
Iron bars, thinner than those in the ARMATURE, placed more or less horizontally and attached to the LEAD CAMES at intervals so as to brace each panel. These were attached to the leads by means of lead ties (latter sometimes made of copper), and extended the width of the panel. They were originally installed on whichever side the window opening was glazed from, depending on the arrangement of sills and walkways.
Pigment containing iron, applied to glass from the early 15th century onward. On firing, it acquired a transparent appearance, similar to SILVER STAIN, but varied from a rosy tint used as a flesh color, to a bright-red orange.
The term is coined from modern oil painting, meaning modeling by means of irregular circular stokes that overlap one another. (cf. CROSS-HATCHING; STIPPLING).
A white-washed board with the CARTOON drawn on it, and used as a pattern for color selection, cutting, painting, and leading.
A transparent yellow stain used on window glasses from at least the 9th century, when a mixture containing a compound of silver and a diluent, such as clay, was applied to the surface of the glass and then fired. Silver stain was almost always applied on the outer surface. The color ranges from lemon yellow to deep amber depending on many variables, including the composition of the glass, the composition of the staining mixture, the firing temperature, and the length of firing. Double stain is sometimes used, producing two tints on the same glass (cf. ENAMEL; POT-METAL).
Layers of paint of varying density blended while still wet. This results in a painterly effect in modeling.
An alloy of lead and tin which has a lower melting point than lead and can, therefore, be used in its molten form to join LEAD CAMES in a stained-glass PANEL.
Painted or engraved ciphers, on either side of the glass; these may repeat within a panel, indicating that they were used for sorting the pieces after firing; or, more rarely, they corresponded to masons’ marks (or pecia marks in manuscript production), to enable the calculation of wages based on jobs completed. These are usually organized in series, like the ciphers that identify gatherings in manuscripts.
The process of using a pointed tool (traditionally the butt of the brush) to scratch details or highlights in painted areas before firing (cf. NEEDLE-WORK; STIPPLING).
A method of shading by first applying a MAT and then letting in minute points of light by dabbing the paint with the butt of the brush (cf. STICKWORK).
A piece of old glass (not necessarily contemporary with the panel) used in restoration to fill a loss. Stopgaps may retain their incongruous painted designs, possibly turned to the outside, or they may be cleaned by acid. Pieces that appear to be from the same series as the panel are so identified in the conservation diagrams. Others may be from any period, up to and including the time the repair was made.
Impressions left on the surface of the glass sheet when it was placed on a bed of straw to cool.
template (also mod)
A cutout shape used as a pattern for cutting a piece of glass; in some cases, a pattern taken from the stonework for use in stained-glass design. Depending on the period, these were presumably cut from parchment, cloth, paper, or metal. By the 19th century, thin brass templates were used because sheet brass was commercially available.
A thickly PAINTED line, typically a contour.
The stone bars forming decoratively shaped tracery lights in the top of a Gothic window, or in a rose.
The ability of glass, even when painted and/or crusted, to transmit light, but without the viewer being able to see clearly through them.
A three-lobed form, whether in vegetation, or the shape of a TRACERY light, or the head of 13th–14th-century light.
Glass produced with an effort to preserve a neutral, colorless state. Invariably, trace elements present within the melting process produced tints that constitute one of the characteristic aspects of M & R GRISAILLE windows.
variants (also rest)
Designs with minor compositional or stylistic changes (cf. REPLICA; VERSION).
Related designs (as of roundels, or decorative elements such as borders and canopies), but with pronounced compositional or stylistic differences between them (cf. REPLICA; VARIANT).
Meaning “we have seen,” this was a small-scale preparatory sketch supplied by the patron or prepared for his approval in the stained-glass shop (cf. CARTOON). The vidimus served as a kind of contractual document, clearly establishing what the glass painter would produce and what the patron would receive. For roundels, Timothy B. Husband defined this as a copy of the design that served as a full-scale cartoon.
white glass: use uncolored.
Spelling and definitions follow Websters 3rd International Dictionary: some definitions are modified. See also Arthur Charles Fox-Davis, A Complete Guide to Heraldry (London, 1929, repr. 1993).
A metal TINCTURE conventionally supposed to be represented by silver but in practice represented by either silver or white.
The heraldic color blue.
One of two or more horizontal stripes on a shield.
The lower part of a field; often used in the phrase, in base.
A BEND from SINISTER CHIEF to DEXTER BASE.
An addition to a coat of arms to mark the position of the bearer with respect to a present or former head of the family (cf. DIFFERENCE).
A figure borne on a field.
A CHARGE consisting of two diagonal stripes meeting at an angle, the point up unless a different position is specified.
The upper part of the field.
Usually a figure placed on a wreath or coronet above both helmet and shield.
Being or related to the side of a heraldic shield or ESCUTCHEON at the right of the person wearing it.
An addition to or change in a coat of arms to distinguish the bearings of two persons which would otherwise be the same (cf. CADENCY MARK).
A heraldic fur consisting of black spots of one of various conventional shaps representing ermine tails set on a white field.
A defined area on which armorial bearings are depicted, usually consisting of a shield.
A broad bar drawn horizontally across the middle of a field.
The center of a heraldic field.
A device that is commonly supposed to be a conventionalized representation of an iris.
The heraldic color red.
A CHARGE consisting of a narrow bar, usually with three pendants, and used especially as a CADENCY MARK to distinguish an eldest son or only son during his father’s life.
Representation of a mantle behind and around a coat of arms.
A star-like CHARGE (not in Webster’s 3rd)
Conventionally supposed to be the color of gold but also represented as any of the various shades of yellow.
A heraldic charge or bearing of simple form, in constant use.
A vertical stripe in an escutcheon.
Divided into two or more parts having different TINCTURES or bearing different coats of arms.
The division of an escutcheon into four or more quarters showing coats of arms brought in by family alliances.
The heraldic color black.
A cross formed by a BEND DEXTER and a BEND SINSITER crossing in the center of the field.
Of or relating to the side of a heraldic shield or ESCUTCHEON at the left of the bearer.
One that acts as a support.
A heraldic metal (ARGENT, OR) color (GULES, VERT, PURPURE, SABLE, AZURE), or fur (ERMINE, VAIR).
A heraldic fur consisting of rows of interlocking upright and inverted shield-shaped or bell-shaped panes alternately ARGENT and AZURE unless other tinctures are specified.
The heraldic color green.[/vc_column_text][/vc_column][/vc_row]