Found a blank prestretched artist's canvas on an upper shelf that had some red wrapping paper on top of it. The paper slightly stained the canvas over time, giving it a "cast." I haven't been painting lately (except with the computer) but got out some old acrylic paints to explore an idea of using that red "cast" as a color. The red is only slightly visible in reproduction--it's subtle, even though the painting isn't terribly subtle.