How did on-shelf painting come into being and what are its advantages?

How did on-shelf painting come into being and what are its advantages? In Europe, easel painting arose in response to religious activities and commercial needs. Medieval parchments and wooden niches were early easel paintings. The widespread use of oil paints in easel paintings in the 15th century gave rise to easel paintings. Nederland miniatures on parchments and single wood panels were already in vogue. In the 16th century, the Venetian school of painting was widely used after stretching canvas on wooden frame. Canvas was the early canvas, and linen came later. In countries like Italy, saints carry religious linens on tight wooden frames for religious activities. Oil painting on canvas has surpassed watercolor painting, egg glue painting, fresco painting and toner painting in terms of expression ability, elasticity of color layer and permanent preservation. In terms of technology, the advantages of oil painting are as follows: The plaster-like oil paints with plasticity have brought flexible and free painting space to painters. Besides the brush, the painter can paint with a scraper and other tools. The painter can make transparent and opaque effects coexist in the full scope of the same picture. Oily pigment drying is slow, the painter can repeatedly alter the picture, and can directly color on the picture, color. Oil painting color bright, conducive to the characterization of the texture of the image, can fully express the complex tonal level of the image, with transparent, vigorous and rich superior effect. Different toners can be used to control the drying time of color, and rich picture texture can be produced by the contrast of the thickness of the color layer and the change of the brush stroke, or painting on the surface of the texture, or adding granular materials in the pigment to express special objects.