You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Martin_Luther

Context:
In the 1530s and 1540s, printed images of Luther that emphasized his monumental size were crucial to the spread of Protestantism. In contrast to images of frail Catholic saints, Luther was presented as a stout man with a "double chin, strong mouth, piercing deep-set eyes, fleshy face, and squat neck." He was shown to be physically imposing, an equal in stature to the secular German princes with whom he would join forces to spread Lutheranism. His large body also let the viewer know that he did not shun earthly pleasures like drinking—behavior that was a stark contrast to the ascetic life of the medieval religious orders. Famous images from this period include the woodcuts by Hans Brosamer (1530) and Lucas Cranach the Elder and Lucas Cranach the Younger (1546).

Question:
When were images being used to promote the spread of Lutheranism?

1530s and 1540s