Philippe Avila considers one of the most beautiful, dramatic and inventive of frame styles. A version of this article was originally published in the December 2006 issue of The Magazine Antiques.
Bartolomé Esteban Murillo (1617-82), The Immaculate Conception, c.1660-65, now Museo del Prado, temporarily exhibited in its original frame, still in Hospital de los Venerables, Seville (with thanks to Jacob Simon)
The 17th century represents the golden age of Spanish frame making; perhaps not surprisingly, since it was also the age of the great Spanish painters – Sánchez-Cotán, El Greco, Velázquez, Zurbarán, Murillo, Ribera, and Valdés Leal, to name just a few. At the beginning of the 17th century, Spanish paintings were essentially religious, marked by splendour and sobriety. Even many portraits, still life paintings and landscapes were related to devotional art. During this time, Spanish painting was greatly influenced by Italian artists, particularly by the school of Caravaggio with its emphasis on naturalism, light, and chiaroscuro.
Alonso Cano (1601-67), High altar of Nuestra Señora de la Oliva, 1629-32, paintings & polychromy of statue by Pedro Legote, Lebrija, Seville
Spanish Baroque frames complemented this interest in light effects through the use of rich carving and reflective gilded decoration, which integrated the painting and the frame into a single decorative whole. As the Spanish golden age also embraced literature, especially of the theatre, the painters of stage designs and ephemeral architecture also played a rôle in the development of Spanish frames of the period.
Sebastian Herrera Barnuevo (1619-71), design for an altarpiece, c.1664-70, ink & pencil on paper. Picture courtesy of Biblioteca Nacional de España
So, too, of course, did altarpieces, or retables, which can be understood as giant frames. Spanish painters and sculptors, most of whom specialized in wood carving, collaborated with tracistas (or draughtsmen who specialized in building and altarpiece design) to create these highly complex compositions, which incorporated paintings, full-sized figures, and sophisticated architectural settings which were intricately carved, gilded, and polychromed. The tendency for lavish decoration increased over the century to the point where it became more important than the actual structure.
Diego Velázquez (1599-1660), Philip IV of Spain, c.1656, o/c, 64.1 x 53.7 cm., National Gallery, London
The golden age of Spanish art was in fact a time of political upheaval, economic crisis, hunger, and rampant inflation. Formed from five smaller states, the kingdom of Spain had been unified into a single entity only since the period 1479-1515, when it came under the rule of the German Habsburgs. During the 17th century it was ruled by the last three Habsburg kings: Philip III (r. 1598-1621), Philip IV (r. 1621-65), and Charles II (r. 1665-1700). From an historical point of view the century represented a period of loss and regression in international politics, compared with the country’s prominence under the Holy Roman Emperors, Charles V (r. 1519-56) and his son Philip II (r. 1556-98) of Spain.
The seat of power was in Castile, but because of their historically independent status, the finances of the old kingdoms of Aragon, Portugal, Navarre, Guipuzcoa, and Vizcaya (Biscay) were not entirely tied to royal authority, and remained under the control of local aristocracies. This left Castile as the only kingdom where royal taxes could be collected to sustain Spanish armies; and high taxation, the costs of wars, and the fall of silver imports from the Vice Royalties of New Spain and Peru led to the collapse of the Castilian economy. The uprising of Catalonia in 1640 led it first to declare itself a republic and shortly after to pay allegiance to Louis XIII of France; it did not return to Spanish dominion until 1653.
Spanish reverse cassetta, c.1650, mortise-&-tenon pinewood, carved polychrome & parcel-gilt, with painted faux ebony & tortoiseshell ‘inlays’, 10 x 6 1/8 ins (probably intended for a small-scale painting on copper). Picture courtesy of Julius Lowy Frame and Restoring Company
Meanwhile, the Church continued to flourish. Governed under a different tax regime, ecclesiastical powers undertook the expansion of churches, monasteries, and lavishly decorated convents. Catholic Counter-Reformation doctrine, spread by such religious orders as the Jesuits, Franciscans, Dominicans and Jeronymites, promoted the idea that spirituality could be increased and the Catholic credo secured from the growing spread of Protestantism by appealing to the emotions and the senses. Thus, staging and theatricality in the visual arts were among the most useful means of conveying church doctrine.
Spanish Baroque frames are too diverse to cover entirely in a single article, so here we will look at the most characteristic types. Madrid, Seville, and Granada were the primary centres of production, both of paintings and frames, at this time. As the recently established capital of the kingdom, Madrid was home to the king and his court. Seville was the port which connected Spain to the New World, and Granada retained iconic importance from its rôle as the last Muslim kingdom in Spain, and the imperial capital under Charles V. A highly-regulated guild system was the true organizer of social life in these cities, and members of at least two guilds or more were involved in the production of frames.
Miguel Adan (1532-1610), Altarpiece of San Juan Bautista, panel with The baptism of Christ showing details of estofado decoration, Monasterio de las Duenas, now Museo de Bellas Artes, Seville
Diego Velázquez (1599-1660), Don Pedro de Barbarana, c.1631-33, o/c, 78 x 43 7/8 ins (198.1 x 111.4 cm.), & detail of polychrome & parcel-gilt frame, Kimbell Art Museum
The structure was usually fabricated by an entallador, a highly-skilled carver in the guild of carpenters . Once made the frame left the workshop of the carpenter/entallador and went to the painter’s workshop. It was primed by an apprentice and then ornamented with gold-leaf and polychrome decoration, often employing estofado (painted and gilded decoration which imitated lavish gold embroidery) .
Bolection frame, Castile or Levante coast, c.1630-60, lap-jointed red pinewood, polychrome & parcel-gilt with estofado decoration, 48 ¼ x 39 ½ ins. Picture courtesy of Julius Lowy Frame and Restoring Company
This task was performed by a pintor estofador y dorador (or decorative painter and gilder), a subdivision within the guild of painters, whose members were not allowed to paint human figures or animals. The latter specialization was only granted to pintores imagineros or ‘painters of images’, who were the highest ranking members of the painters’ guild; this allowed them not only to work on paintings but also on polychrome figure sculptures. Some artists might be accepted into different specializations, and thus might work directly on both paintings and frames. The great importance accorded to frames is further underlined by the fact that many painters designed frames themselves, or were concerned in the production of their frames; for example, Sánchez-Cotán, as witnessed by this statement in his will, dated 1603:
‘…Friar Andrés de Mendoza … brother of the Marquis of Cañete owes me 400 Reales for two images… and two gilded frames completed to perfection… and I make him grace of a small portrait and for the gilding of a frame which belongs to a Magdalene’. 
Bartolomé Esteban Murillo (1617-82), The vision of Saint Anthony of Padua, c. 1656, Seville Cathedral
In 1672 Murillo had the frame for his Vision of Saint Anthony of Padua (in the cathedral of Seville) carved by Bernardo Simón de Pineda (1638-1702) and painted by Alonso Pérez y Pedro de Medina.
Juan de Valdés Leal (1622-90), Exaltación de la Santa Cruz, c.1685, Hospital de la Caridad, Seville
In 1688 Juan de Valdés Leal paid 2,800 reales to José Camacho for carving a frame for his Exaltation of the Holy Cross, located in the choir of the church of the Hospital de la Caridad in Seville.
Bernardo Simón de Pineda (1638-1702), Pedro Roldán (1624-99), Juan de Valdés Leal (1622-90), High altarpiece, 1673, Hospital de la Caridad, Seville
The main altarpiece of the same church was designed by Bernardo Simón de Pineda, carved by Pedro Roldán, and later painted and gilded by Valdés Leal, who signed the contract,
‘Juan de Valdés Leal, master painter of images, gilder, and estofado maker.’
Other artists who designed frames included Juan Martinez Montañés (1568-1649), Alonso Cano (1601-67) , Pedro Roldán (1624- 99), and José Benito de Churriguera (1665-1725).
José Benito de Churriguera (1665-1725), design for an octagonal looking-glass frame, c.1740, ink on paper. Picture courtesy of Biblioteca Nacional de España
Churriguera belonged to a distinguished family of sculptors and carpenters. Four preparatory drawings for altarpieces and frames from his hand are in the Goya Room, Biblioteca Nacional de España, Madrid , one of which is a highly-finished design for an octagonal looking-glass frame. Churriguera and his descendants gave their name to a popular style of architecture and high Baroque decoration, which is characterized by extremely elaborate leaf carving, the use of solomonic (twisted) columns, and a highly-burnished gold finish.
Outset corner frame, Castile or Madrid, late 17th-early 18th century; lap-jointed red pine, carved with Churrigueresque foliation, with cabochons & gems at the sight edge, parcel-gilt & polychrome, with estofado decoration resembling embossed leather, 33 ¼ x 24 ½ ins. Picture courtesy of Julius Lowy Frame and Restoring Company
Frames were made from both local and imported woods. White and red pine were especially appreciated for carving and gilding, but walnut, elm, poplar, pear, chestnut, cedar, and cypress were also among the local species used to make frames. From its colonies in Asia and America, Spain imported many exotic woods, with mahogany, ebony, and vera wood the most appreciated for frames. Frames were usually finely constructed, using lap-joint or mortise-&-tenon joinery. Most were structural interpretations of the Italian cassetta: that is, a simple, lap-jointed flat frame with decorative mouldings derived from classical entablatures .
Reverse profile cassetta, Castile, c.1600-30, lap-jointed pinewood, parcel-gilt & painted with estofado decoration in the corners & centres, 10 ¼ x 7 ½ ins. Picture courtesy of Julius Lowy Frame and Restoring Company
Italian frames of this type had influenced framemaking in Europe since the Renaissance, and examples arrived from Spanish possessions in the Netherlands – Antwerp in Catholic Flanders, Rotterdam, and Amsterdam – and from Augsburg in Germany in the 16th century. They were quickly adopted in Spain and were widely used, until the beginning of the 18th century, in the regions of Castile, Madrid, Andalusia, Aragon, and Majorca. They often have estofado decoration on a black ground, but other background colors are also used, including red, green, blue, and even white. The estofado decoration typically incorporates ornate scrolling acanthus decoration in the corners and centres of the frieze, with minor variations occurring from region to region. In Andalusia and Castile a small cassetta might sometimes be inlaid with tortoiseshell  and have ivory or bronze ornaments.
El Greco (Domenikos Theotokopoulos, 1541?-1614), Antonio de Covarrubias y Leiva, c.1600-02, possibly original frame, cassetta with estofado & foliate decoration at corners & centres, Castile, early 17th century, 26 ½ x 21 ½ ins, Museo de El Greco, Toledo. Photo: Antonio Pareja
The portrait of Antonio de Covarrubias y Leiva by El Greco (above) has a typical Spanish cassetta with estofado decoration, which is probably original to the painting . After the Council of Trent (1545-63), the friezes of such frames were often decorated with biblical texts which guided the viewer in the reading of the painted scene. The cassetta of the early 17th century has relatively narrow mouldings – about three inches wide, depending on the overall size – compared with those made from roughly 1630.
Francisco de Zurbarán (1598-1664), Santa Dorotea, c.1630, pinewood reverse cassetta, parcel-gilt with estofado decoration at corners & centres, c.1620-50, 71 ½ x 40 ins, Museo de Bellas Artes, Seville
Those with wider mouldings, and painted corner and centre cartouches filled with scrolling acanthus, were first made in Naples and Tuscany; but they were also found in most of Spain by the second third of the 17th century (for example, Zurbarán’s Santa Dorotea).
Bolection frame, Andalusia or Seville, 1650-1700, lap-jointed walnut, carved & gilded, Bolognese influence, 22 x 16 ¼ ins. Picture courtesy of Julius Lowy Frame and Restoring Company
Many are of reverse profile (meaning that the highest moulding is on or near to the sight edge) and are entirely gilded, sometimes incorporating punchwork decoration to enhance the light effects, and/or with partial estofado on the frieze. In other cases they incorporate raised stucco designs and/or carved and applied elements such as organic or religious motifs. They were made primarily in Castile around the cities of Valladolid, Toledo, Segovia, Salamanca, and Valencia until about the mid-century, but became less important as artists followed the court to Madrid.
Jan ‘Velvet’ Brueghel (1568-1625), Landscape in paradise with animals, c.1620, ripple frame, Museo de Bellas Artes, Seville
Frames with ripple mouldings – a term used to designate a variety of ornaments, such as fine ripples, waves, and basketweave patterns – were common in Castile, Madrid, Aragon, and Andalusia from the late 16th to the mid-17th century (above). They are closely related to Flemish and German frames of the period and were first made in Spain by immigrants, and later by local masters. They are often fashioned of ebony or ebonized wood, sometimes combined with other veneers such as walnut, boxwood, or tortoiseshell. Oversized examples were often used as looking-glass frames in private residences. In Spanish examples the ripple pattern predominated over basketlike variations.
Johann Liss (c.1597-1631), The satyr & the peasant, possibly c.1623/26, o/c, 52 ½ x 65 7/8 ins (133.3 x 167.4 cm.), ‘Herrera’ frame, c.1630-50, 65 5/8 x 78 5/8 ins, National Gallery of Art, Washington DC
The so-called ‘Herrera’ frame is perhaps the most original Spanish style. The name is derived from that of the architect Juan de Herrera (c. 1530-97), in part because the severe proportions are reminiscent of his style, even though he had nothing to do with this frame design. ‘Herrera’ frames combine mediaeval, Islamic and Baroque ornaments over a cassetta structure, with cabochons, diamonds, dentils, gems, painted foliate motifs, and applied leaves on the frieze, and gadrooning along the edges (as on the Liss, above).
Francisco de Zurbarán (1598-1664), altarpiece (detail), post 1639, Sacristy of the Hieronymite Monastery of Santa Maria de Guadalupe, Extremadura
Francisco de Zurbarán, suite of portraits in the Sacristy of the Hieronymite Monastery of Santa Maria de Guadalupe, completed 1647, Extremadura
Occasionally, they also have ornaments projecting perpendicularly from the sides . ‘Herrera’ frames were used in Andalusia and Extremadura, and to a lesser degree in Madrid, Valladolid, Avila, Palencia, Badajoz and Cáceres, during the second third of the 17th century. Other examples frame Zurbarán’s paintings of 1636-1645 in the sacristy of the Royal Monastery of Santa Maria de Guadalupe, Cáceres, Extremadura.
In 1633 Philip IV and his prime minister Don Gaspar de Guzmán, conde duque de Olivares (1587-1645) undertook the construction of a new summer palace in Madrid, called El Buen Retiro. A gigantic royal compound, it was a showcase for the best art of the period, from the paintings that were hung on the walls to the theatrical performances held in the courtyard, galleries and gardens. Most of the frames made in Madrid from the 1630s to the end of the century were created for the palace or for the households of the nobility, who followed royal taste closely. The frames made in Madrid can be distinguished from those made in Andalusia, especially those from Seville, because black polychrome or ebonized finishes predominate, and the gilded frames are a duller gold and so are less showy. They also have a thinner gesso priming than their southern counterparts.
Moulding frame, Andalusia or Madrid, c.1660-75, pinewood with ebonized mahogany, mortise-&-tenon construction, carved & parcel-gilt, 11 x 8 1/8 ins.; ornament & finish similar to an Italian ‘Salvator Rosa’ frame, used with a Spanish Baroque profile. Picture courtesy of Julius Lowy Frame and Restoring Company
During this period Spanish frames still took their inspiration from Italy – particularly Naples, which was then a Spanish territory, as well as Rome, Venice, and Tuscany. Italian painters worked for the court, and many Spanish artists travelled to Italy to study the masters and to visit Rome, contributing to the interchange of ideas. Influenced by the decoration on Italian models, carved leaves became another archetypal motif on Spanish frames, including not only Italianate acanthus leaves but also lotus flowers, cabbage-like and fleshy cactus leaves, sometimes carved in the round and sometimes applied to a cassetta structure. Cluster ornaments or masks were sometimes substituted for leaves on the corners, and estofado decoration might also be included to reinforce visual aspects of the framed painting.
Alonso Cano (1601-67), Madonna of the Rosary, 1665-67, o/c, 350 x 213 cm., Málaga Cathedral
Alonso Cano (1601-67), designs for cartouches & ornaments, c.1640, ink & pen on paper. Picture courtesy of Biblioteca Nacional de España
Leaf frame attributed to the circle of Alonso Cano, Madrid, c.1640-50, lap-jointed walnut, carved and gilded, 12 3/8 x 9 ¼ ins.; related to the drawings by Cano (above). Picture courtesy of Julius Lowy Frame and Restoring Company
Alonso Cano (1601-67), The martyrdom of St John, c.1667, pen, brush & brown ink on paper, 8 13/16 x 5 5/8 ins (22.38 x 14.29 cm.), Los Angeles County Museum of Art
The sculptor, painter and architect Alonso Cano, who worked during the 1650s, is significant here because he developed a fleshy style of leaf of great inventiveness which he brought to the court in Madrid from Seville, contributing to the expansion of this decorative style.
Frame related to French Louis XIII styles, Madrid or Andalusia, c.1650, mortise-&-tenon walnut, carved & gilded with cross-cut acanthus moulding, 31 ½ x 24 ins. Picture courtesy of Julius Lowy Frame and Restoring Company
Some frames are decorated with running mouldings of gilded leaves (above), reminiscent of French Louis XIII-style frames; whilst a variation which was popular in and around Seville in the last quarter of the 17th century has richly-gilded scrolling acanthus leaves, an interpretation of Louis XIV patterns, which were frequently highly burnished.
Spanish Baroque frames cannot be understood without referring to imports from Mexico. A guild of carpenters was created in Mexico City between 1580 and 1650 which was based directly upon the guild in Seville, and included a large number of craftsmen who had emigrated from that city . Spanish artists were introduced to the arts of Asia by way of Mexico. Exports to Spain from China, India, Japan and the Philippines stopped first in Acapulco on Mexico’s west coast, carried by land through the narrower part of the country and then re embarked in Veracruz on the east coast towards Spain. In Mexico, south eastern techniques and patterns mingled with the work of local artists, and also with European fashions, resulting in many colonial masterpieces such as frames and furniture made with Mexican lacquer, or maque, many of which were inlaid with mother-o’-pearl, and which were exported to Spain from around 1670 . In addition, luxury materials widely used in 17th century Spanish frames, such as tortoiseshell, were imported from Mexico .
Unknown artist, St James Matamoros, c.1600, 8211/16 x 551/8 ins (210 x 140 cm.), in frame of c.1680, Hispanic Society of America, New York City
A Mexican retable relief representing Saint James Matamoros of about 1680 is surrounded by a Mexican frame of characteristic ‘Herrera’ design made at the end of the 17th century, by which time such frames were somewhat outdated in Spain (although still appreciated).
Today, these various Baroque frames retain the theatricality and elegance which complement both Spanish and other European paintings, although framing or refraining Old Masters is not the only possibility for which they may be employed.
Salvador Dalí (1904-89), Hispano-Flemish frame, 17th century, veneered in ebony, with modern looking-glass, Dalí House, Port Lligat, Spain
Salvador Dalí, for example, expressed a strong interest in Dutch and Spanish masters of the 17th century, which he reflected not only in his paintings but also in the frames he chose for them, many of which are reproductions or period frames in such styles, some of which were selected by his lover Gala. Moreover, several 17th century Dutch frames with ebonized surfaces and ripple mouldings are used around looking-glasses in his residences in Spain, at Port-Lligat near Cadaqués (above) and at Púbol.
Max Kuehne (1880-1968), Village scene, liveauctioneers, 5 May 2018, Lot 12
The influence of Spanish frames on American framemakers should not be ignored either. The Arts and Crafts artists Max Kuehne (1880-1968) and Frederick Harer (1879-1949) both traveled to Spain . Kuehne lived in Granada for several years and Harer visited the island of Majorca, near the Catalan coast. Both made frames which show their great attraction to the simplicity of the cassetta, and both favoured decoration derived from Spanish Baroque frames.
Frederick Harer (1879-1948), Silver-leaf reverse cassetta, early mid 20th century, Lowy Collection
Their inventiveness resides more in their adaptation of technical aspects of Spanish frame decoration, such as the use of silver leaf over red bole , a combination which was often used on 17th century Andalusian frames, but was rarely seen in American framemaking. Experimentation led to gold-toned variations and several grades of hues, which were reinforced and protected by thin layers of translucent coloured varnishes . More recently, contemporary American artists such as Julian Schnabel (1951-) have discovered the strong personality of 17th century Spanish frames. Indeed, they remain among the most fascinating of all European frames and deserve renewed attention.
PHILIPPE AVILA, a scholar of Spanish frames, is also a giltwood and frame restorer and conservator. He can be contacted by e-mailing email@example.com
Reverse frame, Castile, 1600-50, lap-jointed red pinewood, gilded, with carved & punchwork acanthus leaves, punchwork ground & detail, carved cabochons & gems at the sight edge, 8 3/8 x 5 ½ ins. Picture courtesy of Julius Lowy Frame and Restoring Company
FACTUM FOUNDATION & SPANISH FRAMES: an additional note by The Frame Blog
In an interesting coincidence for this article, the current newsletter from the Factum Foundation contains a short piece on the company’s recent (2017) recording of two paintings and their frames: Murillo’s Miracle of the loaves and fishes, and Moses and the water from the rock of Horeb; both in the Hermandad de la Santa Caridad in Seville.
Bartolomé Esteban Murillo (1617-82), The miracle of the loaves and fishes, and Moses and the water from the rock of Horeb, both 1669-70, 236 x 575 cm., Hospital de la Caridad, Seville
‘The paintings, which had been removed from their usual locations high up on the walls of the church for conservation by the Instituto Andaluz de Patrimonio Histórico (IAPH), were recorded using the Lucida 3D scanner and composite photography, whilst their frames were recorded using photogrammetry.
High resolution colour reproductions have been made from the data at a 1:1 scale; these will be displayed in the Hermandad de la Santa Caridad in a setting which will allow visitors to examine these magnificent works at close range.
Some very exciting developments are being finalised to record, share and communicate the importance of paintings of the Spanish Golden Age….’
Recording the frames of the two Murillo paintings
A detail of the 3D model of one of the frames in progress
There is more information about this project on the Factum Foundation website.
 Entallador is the Spanish word for wood carver or, better still, chiseler. Their status was high because of their ability to draw.
 The word estofado comes from the Latin stuppa, which is the tow or coarse part of flax. In 16th and 17th century Spain, estofado referred specifically to polychrome decoration created using a combination of water, rabbit-skin glue and pigment applied over burnished water gilding. When dry, the painting is scratched with a boxwood stick called a grafio to reveal the gold leaf below, giving the appearance of fabric embroidered with gold threads. To designate the same technique Italians use the word sgraffito and Mexicans hermoseado.
 See Julio Cavestany, Discurso leido en la recepcion en la Real Academia de Bellas Artes de San Fernando, Madrid, 1941, pp. 20-22 (translation of quotation by the author).
 There are ten drawings by Alonso Cano for different elements of retables and frames, including pilasters, columns, cartouches, leaf designs, brackets, and entablatures, in the Goya Room, Cabinet of Drawings, Maps and Prints, Biblioteca Nacional de España, Madrid (nos. Dibl6/39/30-16/39/33, Dibl5/2/8, Dibl8/1/880, Dibl8/1/881, Dibl6/39/49, Dibl8/1/898/2, Dib18/1/879).
 Biblioteca Nacional de España, Madrid: nos. Dib14/48/1, Dib15/10/6, Dib15/85/82, Dib18/1/849.
 See Timothy J. Newbery, George Bisacca & Laurence B. Kanter, Italian Renaissance Frames, Metropolitan Museum of Art, New York, 1990, p. 105.
 The painted trompe l’oeil frame with faux tortoieshell ‘inlays’ shown earlier indicates what the (generally small) frames veneered with genuine shell looked like.
 The frame, which fits perfectly, retains its original size, and there are no traces of holes suggesting a different hanging. Decoration, wood type, joinery, and craquelure are consistent with other examples commonly found in Toledo at the time. There is no evidence to attribute the frame to El Greco or his workshop; however, the Greek-born painter was the first artist to introduce a Baroque influence in the altarpiece for the main altar of the Capilla de San José in Toledo.
 An exceptional example frames Bartolomé Esteban Murillo’s The Immaculate Conception in the Museu Nacional d’Art de Catalunya, Barcelona.
 Efrain Castro Morales, ‘Origen de algunos artistas y artesanos europeos de la region de Puebla-Tlaxcala’, Actas del XXIII Congreso Internacional de Historia del Arte, Granada, 1973, quoted in Maria Pia Timon Tiemblo, El marco en España, P.E.A., Madrid, 2002, p. 267.
 There are several examples of this kind in the Museo de América, Madrid, designed as a cassetta with outset corners, typical of frames in the style of Charles II. They are decorated with multicoloured lacquer and inlaid with mother-o’-pearl.
 Turtles were fished in the Gulf of Mexico, and Europeans learned the techniques of working with tortoiseshell from the Puebla Indians.
 For additional information on the influence of Spanish frames in the United States, see Tracy Gill, ‘The American frame: from origin to originality’, Gill and Lagodich Fine Period Frames, New York, 2003.
 Bole is a type of finely ground clay which is mixed with rabbit-skin glue as a substrate for adhering silver or gold leaf. Several colours are known, such as red, red-brown, yellow ochre, black, and blue, but the predominant colours on 17th century Spanish frames are the first three of these.
 Thanks to trade with China, technical advancements led to the creation of lacquer substitutes, which were more easily available to Western artists, and were applied to both frames and retables.