A story is told of how Hubert van Eyck painted a picture upon which he had lavished his usual painstaking care.

But when he put it in the sun to dry, the panel cracked down the middle.

After this disappointment Hubert went to work and invented a new substance with which colours are made liquid, a 'medium' as it is called, which when mixed with colour dried hard and quickly.
It was possible to paint with the new medium in finer detail than before, and the Flemish artists universally adopted it.

While very little was remembered about the facts of Hubert van Eyck's life, his name was always associated with the discovery of a new method of painting, and on that account held in great honour.
The 'Three Maries' is in many respects the most attractive of the pictures ascribed to Hubert, but his most famous work was a larger picture, or assemblage of pictures framed together, the 'Adoration of the Lamb,' in St.Bavon's Church at Ghent.

It is an altar-piece--a painting set up over an altar in a church or chapel to aid the devotions of those worshipping there.