These frescos on the church ceiling were painted using the wet plaster technique.

frescos 是 fresco 的复数形式，fresco 来自意大利语，指直接在湿灰泥墙面上绘制的壁画。这种技法要求画家在灰泥未干时快速作画，颜料会渗入墙面，干燥后形成持久的色彩。