Panel painting 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, almost transparent, brushstrokes. Thin layers of paint would be used to create volumetric forms. 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
The medium is the message as an example, he argued that the way this medium played with conceptions of speed and time transformed "the world of sequence and connections into the world of creative configuration and structure." Therefore, the message of the movie medium is this transition from "lineal connections" to "configurations". Extending the argument for understanding the medium as the message itself, he proposed that the "content of any medium is always another medium" – thus, speech is the content of writing, writing is the content of print, and print itself is the content of the telegraph. McLuhan understood "medium" in a broad sense.