Perhaps the most dramatic, or at least widely acclaimed, breakthrough in the Renaissance was in the realm of art, in particular painting. Not only did Renaissance art reflect growing concern with secular subjects, it involved new artistic tools and techniques that more accurately portrayed those subjects. Pre-eminent among those tools was the shift from tempera (egg based) paints painted on wood or as frescoes on walls to oil based paints applied to canvas.
Frescoes were wall paintings applied to wet plaster that set into the wall when dry. While this did help preserve the painting, it had several drawbacks. First of all, frescoes dried quickly so an artist had to plan his work thoroughly in advance, since to change any mistakes involved redoing the whole painting. This made frescoes stiff and less spontaneous. Also, the rough surface of a plaster wall made it hard to render details, forcing the artist to use a pointed brush and even at times to stipple the surface dot by dot. To deal with these limitations, an artist would divide the wall into sections, one for each day’s work. He would also do extensive preliminary drawings of the planned painting on the wall.
Tempera was the type of paint used in frescoes, consisting of egg mixed with pigment. This created a light, but somewhat limited range of colors. It dried quickly, which prevented the layering of paints and the subtle shading (known as chiaroscuro) of a painting.
Oil based paints were developed as early as the 1100s and were first widely used in the Low Countries in the early 1400s. Since it dried slowly, oil had three major advantages over tempera. First, it could be layered, which made possible the use of chiaroscuro & sfumato (a technique giving a painting a misty, foggy, or smoky effect). Second, artists could mix colors with oils, giving them a broader and richer palette to work with than ever before. Finally, as evidenced by X-rays of paintings, artists could, and did, change mistakes, thus letting them be more spontaneous in their work.
While oil paints were widely used in the North, they did not reach Italy until about1475. Artists in Venice were the first Italians to use oil enthusiastically, their paintings being distinguished by the rich reds they often used. From Venice, the use of oil based paints spread rapidly across Italy.
Canvas replaced walls as a medium for painting had as dramatic an impact on art as oil replacing tempera. Not having to rely on walls, especially Church walls, for a painting surface, artists could paint smaller portraits and paintings with other themes, opening up wider markets for their talents. Canvas was also more portable, so artists could work in the privacy of their own studios where they could better attract models (especially for nude paintings). These two factors, plus growing middle class patronage, led to a commercial revolution in art and the end of the dominance of the Church, kings, and nobles who previously had the money and walls artists needed. Consequently, they could now pursue a much broader range of topics for paintings than ever before.
New techniques in painting also helped transform Renaissance art. The most important of these was linear perspective, which allowed artists to attain three-dimensional effects on a two dimensional surface. Without it, paintings were crowded and limited in the number of people and details that could be represented. Greek and Roman paintings had achieved a high degree of perspective, but their techniques were lost during the Middle Ages. True linear perspective was first attained around 1420 in a remarkable experiment done by Filippo Brunelleschi, the same man who had designed the dome of Santa Maria del Fiore in Florence.
Brunelleschi painted Florence’s Baptistery from the perspective of the facing cathedral doorway. He then drilled a hole through the vanishing point of the painting (which faced the Baptistery) and set a mirror in front of it. As someone in the cathedral doorway looked toward the Baptistery through the peephole, Brunelleschi could raise or lower the mirror so the viewer was alternately seeing the Baptistery or the reflection of the painting. Supposedly, his painting and mastery of perspective were so good, viewers could not tell the difference between the real Baptistery and the reflected painting. This dramatic demonstration, plus more secular themes, proper proportion, and attention to details, triggered a virtual revolution, not just in art, but in a whole new way of viewing the world that has become a vital part of our civilization. In the 1600s, this new perspective on the world would help lead to the Scientific Revolution.