The style of painting grew directly out of medieval painting in tempera, on panels and illuminated manuscripts, and other forms such as stained glass; the medium of fresco was less common in northern Europe. The medium used was oil paint, which had long been utilised for painting leather ceremonial shields and accoutrements because it was flexible and relatively durable. The earliest Netherlandish oil paintings are meticulous and detailed like tempera paintings. The material lent itself to the depiction of tonal variations and texture, so facilitating the observation of nature in great detail.