Phrase is a correct discretion of the true fresco technique

I believe the answer would be Applying paint to a wet plaster wall. Correct me if i didn't answer the question in the right form.

Fresco (plural frescos or frescoes) is a technique of mural painting executed upon freshly laid, or wet lime plaster. Water is used as the vehicle for the dry-powder pigment to merge with the plaster, and with the setting of the plaster, the painting becomes an integral part of the wall.