What did the use of a canon of proportions allow ancient egyptian artists to do?

The Ancient Egyptian artists sculptured, inscribed or painted figures, their proportions would be determined by a canon of proportions. Up until the end of the New Kingdom's 26th Dynasty, the Ancient Egyptians used a grid that measured 18 units to the hairline, or 19 units to the top of the head. The height of the figure was usually measured to the hairline rather than the top of the head, this part of the head often being concealed by a crown or head piece making it difficult to base a canon of proportions on.

This has to be at least 20 words so :