Which artistic convention was most important to Gothic artists

It was to comunicate a religious message

Explanation:

Like the other medieval painting styles, Gothic was born to serve as a representation of the fears, beliefs, and ideas from that period. The religious dominance represented by the Catholic Church found a fertile terrain on the Gothic paintings. Because of the naturalistic approach of this style, the religious message was more realistic, trying to capture the essence of the portrayed moment.

Communicating a religious message