Everyone is correct. It's a string quilt made by sewing strips onto a foundation like newsprint, then cut to size with a 60 degree triangle ruler. The different shades of one color are giving it the 3-D effect. My church quilting group made the strings in just scrappy fabrics, but you still get a slight 3-D effect, just not to the degree you get when you use the different shades from light to dark. I'm thinking you could sew long strips together of what looks like six colors going from light to dark. Then, take your 60 degree ruler and cut one, flip and cut another, flip and cut the third and so on. Then, the way you assemble them, is what gives this effect. Focus on where the light to dark is pointing to see how to sew them together.