Panel painting is very old; we know it was a very prestigious medium in Greece and Rome, but only very few examples of ancient panel paintings have survived. A series of 6th century BC painted tablets from Pitsa (Greece) represent the oldest surviving Greek panel paintings. The first century BC to third century AD Fayum mummy portraits, preserved in the exceptionally dry conditions of Egypt, provide the bulk of surviving panel painting from the Imperial Roman period - about 900 face or bust portraits survive. The Severan Tondo, also from Egypt (about 200AD) is one of the handful of non-funerary Graeco-Roman specimens to survive. Panel painting has always been the normal support for the Icons of Byzantine art and the later Orthodox traditions, the earliest of which (all in Saint Catherine's Monastery, Mount Sinai) date from the 5th or 6th centuries, and are the oldest panel paintings which seem to be of the highest contemporary quality. Encaustic and tempera are the two techniques used in antiquity; encaustic largely disappears after these early Byzantine icons.
In the late 12th century panel painting experienced a revival in Western Europe because of new liturgical practices—the priest and congregation were now on the same side of the altar, leaving the space behind the altar free for the display of a holy image—and thus altar decorations were in demand. The earliest forms of panel painting were dossals (altar backs), altar fronts and crucifixes. All were painted with religious images, commonly the Christ or the Virgin, with the saints appropriate to the dedication of the church, and the local town or diociese, or to the donor. The donor and members of his family are also often shown, usually kneeling to the side.
Italy in the 13th and 14th centuries was a great period of panel painting, mostly altarpieces or other religious works. However, it is estimated that of all the panel paintings produced there, 99.9 percent have been lost. The vast majority of Early Netherlandish paintings are on panel, and these include most of the earliest portraits, such as those of Jan van Eyck, and some other secular scenes. However, one of the earliest surviving oils on canvas is a French Madonna with angels of about 1410 in the Gemäldegalerie, Berlin, which is very early indeed for oil painting also.
. By the 15th century with the increased wealth of Europe, and later the appearance of humanism, and a changing attitude about the function of art and patronage, panel painting went in new directions. Secular art opened the way to the creation of chests, painted beds, birth trays and other furniture. Many such works are now detached and hung framed on walls in museums. Many double-sided wings of altarpieces (see picture at top) have also been sawn into two one-sided panels.
Canvas took over from panel in Italy by the first half of the 16th century, a change led by Mantegna and the artists of Venice (which made the finest canvas at this point). In the Netherlands the change took about a century longer, and panel paintings remained common, especially in Northern Europe, even after the cheaper and more portable canvas had become the main support medium. The young Rubens and many other painters preferred it for the greater precision that could be achieved with a totally solid support, and many of his most important works also used it, even for paintings over four metres long in one dimension. His panels are of notoriously complicated construction, containing as many as seventeen pieces of wood (Het Steen, National Gallery, London). For smaller cabinet paintings, copper sheets (often old printmaking plates) were another rival support, from the end of the 16th century, used by many artists including Adam Elsheimer. Many Dutch painters of the Golden Age used panel for their small works, including Rembrandt on occasion. By the 18th century it had become unusual to paint on panel, except for small works to be inset into furniture, and the like. But, for example, The National Gallery in London has two Goya portraits on panel.
Many other painting traditions also painted, and still paint, on wood, but the term is usually only used to refer to the Western tradition described above.
The technique is known to us through Cennino Cennini's The Craftsman's Handbook (Il libro dell' arte) published in 1390, and other sources. It changed little over the centuries. It was a laborious and painstaking process:
The usual ancient painting technique was encaustic, used at Al-Fayum and in the earliest surviving Byzantine icons, which are at the Saint Catherine's Monastery, Mount Sinai. This uses heated wax as the medium for the pigments. This was replaced before the end of first millennium by tempera, which uses an egg-yolk medium. Using small brushes dipped in a mixture of pigment and egg-yolk, the paint was applied in very small strokes. Because tempera (like encaustic) dries quickly and is not conducive to mistakes, each stroke had to be perfect each time. This exacting perfection shaped the nature and style of the art produced.
By the beginning of the 15th century, oil painting was developed. This was more tolerant, and allowed the exceptional detail of Early Netherlandish art. This used a very painstaking multi-layered technique, where the painting, or a particular part of it, had to be left for a couple of days for one layer to dry before the next was applied.
Wood panel is now rather more useful to art historians than canvas, and in recent decades there has been great progress in extracting this information - and many fakes discovered and mistaken datings corrected. Specialists can identify the tree species used, which varied according to the area where the painting was made. Carbon-dating techniques can give an approximate date-range (typically to about a range of about 20 years), and dendrochronology sequences have been developed for the main source areas of timber for panels. Italian paintings used local or sometimes Dalmatian wood, most often poplar, but including chestnut, walnut, oak and other woods. The Netherlands ran short of local timber early in the 15th century, and most Early Netherlandish masterpieces are Baltic oak, often Polish, cut north of Warsaw and shipped down the Vistula, across the Baltic to the Netherlands. Southern German painters often used pine, and mahogany imported into Europe was used by later painters, including examples by Rembrandt and Goya.
In theory dendro-chronology gives an exact felling date, but in practice allowances have to be made for a seasoning period of several years, and a small panel may be from the centre of the tree, with no way of knowing how many rings outside the panel there were. So dendro-chronological conclusions tend to be expressed as a "terminus post quem" or an earliest possible date, with a tentative estimate of an actual date, that may be twenty or more years later.