Why Jan van Eyck's Ghent Altarpiece Is a Masterpiece of Detail

Large religious paintings from this period often took the form of polyptychs—multi-panel works designed for cathedral altars. These works featured a central panel (predella) at the base containing narrative scenes, with additional scenes painted on the back panels. Viewers could walk completely around the altarpiece, with the predella providing focus for kneeling worshippers during prayer. Duccio's massive 15x20 foot altarpiece depicted Mary as Queen of Heaven, demonstrating how scale and spatial arrangement served both artistic and devotional purposes.

Medieval altarpieces often consisted of polyptychs (many panels) or triptychs (three panels) that could swing open to reveal additional scenes. These multi-paneled works displayed complete narratives of Christ's life or Mary's life, with scenes arranged to unfold progressively. The polyptych format allowed churches to display different scenes depending on liturgical seasons, creating dynamic visual experiences that engaged worshippers throughout the year.

A polyptych is a multi-panel painting consisting of four or more panels, historically used in 15th-century Flemish altarpieces to depict biblical scenes for illiterate audiences; contemporary artist Bob Buridge creates polyptychs by painting all panels simultaneously using layers of collage, gel medium, and paint to explore themes of equality, with the technique offering practical benefits for transporting multiple small canvases rather than one large piece.

A polyptych is a series of panels with complicated carpentry that shows a central image, usually of the Virgin but sometimes of Christ or episodes relating to them. The main components include the central panel (pala), side panels with saints, smaller saints in pilasters, religious figures above, and the cimasa (top section). Below the main panel is the predella, which served as the base on which the altarpiece sat and typically contained scenes from the life of Christ.

Structures called retablos were developed on altars, including triptychs and polyptychs with central panels and hinged wings. The more wings a polyptych had, the longer biblical stories could be depicted. These altarpieces served two functions: enabling illiterate people to read biblical stories and creating mystery by being hidden during weekdays and revealed during festivals. In medieval Western churches, a hierarchy of altars developed with main and side altars. This occurred because each priest needed to celebrate Mass daily, and a single altar could only host one service per day. Large monastic complexes required many additional altars. The main altar was reserved for festive services and major community events, while daily services were conducted at side altars. Altars were required to contain relics of saints and martyrs.

Medieval art used everyday objects as sacred symbols—the key represented authority embodied by St. Peter, the mirror held duality between truth and vanity, the scale symbolized divine judgment, and the book represented divine wisdom. Early Christians used cryptograms as secret visual language—the fish (ichthys) was an acronym for 'Jesus Christ, Son of God, Savior,' the chi-rho was adopted by Constantine as imperial triumph, and the alpha and omega symbolized Christ's eternal existence. For the Virgin Mary, artists created intricate symbols: the hortus conclusus represented her perpetual virginity as fortress of faith, the tower of ivory symbolized her beauty and moral fortitude, and the sealed fountain represented the virgin birth. Demonic imagery served as teaching tools—demons were strategically placed on cathedral exteriors as spiritual defenders. The dragon represented Satan's overwhelming power, the serpent symbolized cunning deception, and colors carried specific meanings: red represented hellfire, green represented disease and envy, light symbolized God and spiritual clarity, while darkness represented ignorance and separation from God. Saintly attributes created a visual shorthand system where each major saint was given a specific object—St. Sebastian with arrows, St. Catherine with her broken wheel, St. Paul with his sword. The pilgrim symbolized every human soul navigating toward salvation, the knight represented the spiritual life with armor symbolizing the armor of God, and musical instruments carried specific meanings: the harp represented divine harmony, the trumpet symbolized final judgment, and the organ embodied the church itself.

Medieval religious art uses consistent symbolic motifs to convey theological concepts. The Annunciation scene depicts Mary being told she will have a child while remaining a virgin, with the object over her head being a circle of clouds containing two circles of small angels—a common way of representing God visible in medieval paintings. The so-called laser beam represents the Holy Spirit's impregnation of Mary, often symbolized by a dove. Another famous painting shows Jesus and God holding what appears to be Sputnik's antenna, but theologians explain this represents the Earth, which is round because the biblical concept of creation attributes the world's creation to the Father, Son, and Holy Spirit. The creation globe became a very common symbol in medieval art.

In medieval times when most people were illiterate, churches used iconography (religious paintings and sculptures) to teach biblical stories and religious concepts. This visual approach allowed illiterate congregants to understand religious narratives by viewing images arranged in a specific sequence depicting events from the Old and New Testaments. Before the Great Schism of 1054, both Western and Eastern churches used iconography and mosaics. After the schism, Western churches increasingly adopted three-dimensional statues while Eastern churches maintained prohibition on three-dimensional religious images. Seraphim (six-winged angels) appear in Christian churches regardless of tradition, arranged hierarchically with saints at the bottom, angels above, archangels higher, and seraphim at the top, with Christ typically at the center.

Medieval Christian art served as a sophisticated visual language for communicating complex theological ideas to ordinary people. Artists employed diverse strategies including depicting plague-afflicted Jesus for psychological comfort, transforming wounds into female reproductive imagery to symbolize Christianity's birth, and creating bizarre wine-to-blood transformations to demonstrate Eucharistic doctrine. These approaches reveal how medieval Christians used visual paradox and explicit symbolism to make abstract spiritual concepts emotionally accessible and intellectually comprehensible.

Objects gradually became subjects for artists not as appendages but as subjects in their own right, including globes, skulls, musical instruments, fruits, and vegetables. The emergence of still life as a genre marks this transition. Iconography examines symbolism attached to particular things and creatures, with meanings understood in historical context. The Bible and mythology were crucial reference points, with literary references commonly held knowledge in the period. Attributes like Saint Catherine's wheel or Saint Sebastian's arrows identify figures. Objects indicate economic exchange and global trade, with items like coral necklaces opening possibilities for understanding colonialism and trade. Many works are small devotional images intended for personal use rather than altarpieces. In the 15th century, images were precious and rigorously contemplated as objects of meditation, central to faith as catalysts for spiritual reflection. The cult of relics privileged objects like splinters of the cross, drops of Christ's blood, and the tongue of Saint Anthony as having literal powers for the faithful. Fra Angelico's workshop produced small-scale devotional images using gold leaf for heavenly backgrounds. Traditional crucifixion iconography includes halos, diverse crowds with multicultural indicators, and specific figures like Longinus (from Greek for lance). The skull of Adam represents humanity's original sin, with the crucifixion site sometimes thought to be where Adam was buried.

Artists can transition from tempera (темпера) to oil painting by using a protective layer (лаком межслойной) between layers. The artist explains that while this technique is possible, she personally prefers working directly in oil paints for comfort and better results. Each artist should choose the medium that works best for their style.

Oil painting offered several advantages over tempera, the traditional medieval painting medium. Oil paint's slow drying time allowed artists to blend colors smoothly and make corrections after the paint had dried. The medium's transparency enabled artists to build up multiple layers of color, creating depth and luminosity. These technical advantages made oil painting particularly suitable for detailed works like 'St. Jerome in the Study,' where the artist could achieve extraordinary richness in color and texture.

In 15th-century Flanders, artists mixed pigment with linseed oil on marble slabs, creating a new medium. Before oil paints, they used tempera (pigment mixed with egg yolk), which dried quickly and produced flat, graphic colors with clear contours. Oil paints became plastic, dried slowly, and allowed working in layers. Artists could apply thin, transparent layers over each other, creating depth, volume, and light. This technique—glazing—allowed light to pass through upper layers and reflect from lower ones, creating inner glow. Skin on Van Eyck's portraits appears alive because of this. Different pigments dried at different rates and changed color over time, requiring artists to keep detailed records of mixing proportions and drying times. Oil paints freed artists from the tyranny of speed that tempera demanded. With tempera, artists had to work quickly as it dried in minutes. With oil, they could work slowly, thoughtfully, correct mistakes, and change compositions on the fly. This gave time for reflection and made art deeper, more complex, and more psychological.

The transition from tempera to oil painting represents a fundamental technological revolution in art history. While tempera uses egg yolk as a binder, oil painting employs oil (typically linseed oil) as the medium, which can be diluted with turpentine or other solvents. This change allowed for greater luminosity, richer color saturation, and the ability to blend colors more smoothly. Oil paint dries more slowly, giving artists more time to work and make adjustments. The technique enabled the creation of subtle glazes and the rendering of complex light effects that became characteristic of Renaissance painting. This technological innovation transformed artistic practice and opened new possibilities for visual representation.

Painting has known all types of supports throughout history, achieving its most broad and monumental expression in great mural compositions. One of the oldest pictorial procedures is encaustic or painting with wax, well known by Greeks and Romans but of short presence in painting history due to the difficulty of its preparation and application. It consists of a mixture of wax with resin or pol, to which once heated and melted, essence of turpentine is added. The mixture of color pigments with gum arabic allowed the delicacy and chromatic transparency of miniatures, which during the Middle Ages mainly illuminated sacred texts in the West. On a parchment sheet, the composition of a scene is drawn and fitted, with the contours and interior fields of figures traced, then color applied sectorially. The most important medieval text on painting technique, by Cennino Cennini, said of Giotto that he had translated the art of painting from Greek to Latin, dominating this art as no one had done before. The technique of painting in tempera is very ancient and knew its golden age during the Middle Ages until the technique of oil painting emerged. Tempera uses egg as the vehicle and binder for color pigments, with the yolk carefully separated and mixed with distilled or purified water to add color. Each master had their own recipes, with some adding gum, oil, or resin to retard the drying of the painting and work more freely. Along with the rapid drying of egg tempera, this technique has other advantages such as its durability and especially the tonal possibilities of color. It was frequently used as a base for oil painting, giving rise to a mixed technique used by many painters in the 15th century. The technique of egg tempera was used as preliminary painting in an unmistakable white tone in the famous portrait known as The Man with the Red Turban, by the Flemish painter Jan van Eyck, now in the National Gallery of London. When applying red color in different layers, these act by transparency, revealing the modeling, details, and shadows previously defined on white. The painter then secures all contours and begins to enhance the peculiar interior relief of the turban, reinforcing that matized orography of the folds that became one of the most characteristic features of what are known as Flemish primitives. By successive transparencies and reinforcement of shadows, the volume of the turban acquires a three-dimensional force difficult to surpass. Throughout the 16th century, both oil painting technique and the use of canvas as support for painting became established. Canvas is normally of linen and requires previous preparation with a paste of glue to give the imprimatura. The imprimatura can range from very light to very dark tones, having a decisive effect on the final chromatism of the work, so each artist carefully chooses it according to the technique to be employed. In the copy of this self-portrait by Titian in the Prado Museum, the imprimatura responds to a medium tone, and on it with the loose technique that characterized the final work of the great Venetian master, colors are applied while conserving the imprimatura as base and chromatic reference. Colors are diluted in linseed oil, succeeding the rapid brushstrokes with light touches that bring out and accentuate the lights of the work.