It's all fleece. Just different colors. (Though, the lighter blue I found was more of a silk-finished fleece than the other blues I used and presented a whole host of problems because it didn't want to go through the machine well. Remnants. Cest la vie!)You need 3 colors for each panel cut in a total of 5 pieces: your main TARDIS blue, a darker blue, and a lighter blue. The main blue needs to be cut smaller than the actual panel size, while the darker blue needs to be cut in strips to make up the rest of the size and sewn in one corner, meeting at a 45-degree angle at the corner, and the lighter blue does the same in the opposite corner.For example: My whole panels were calculated at 17.701 inches high by 16.087 inches wide. For the quilt I simplified the measurement to 18x16 inches. From that, I took 1 inch from each side and cut my main blue pieces at 17x15 inches (plus seam allowance, obviously, but I'm just illustrating here). Therefore my contrasting color pieces were then cut in trapezoids, with the outside edge being 18 inches in length and the inside being 17 inches with a 45-degree cut connecting the corners for the top and bottom of the panel, and the other trapezoids on the left and right side of the panel being 16 inches on the outside and 15 inches on the inside; there should be one of each trapezoid measurement in each contrasting color.From there, you just need to sew matching length sides to each other, and the 45-degree angles shut. When you flip it over and lay it flat you should have the completed panel in the size you need with the illusion of depth!crude representation of the basic idea: sta.sh/01r4uzljter9?recent_pre… I put the darker blue on the top and the right sides of my panels, to imply a light source above and to the right of the TARDIS, but you can do it in any configuration you like as long as the contrasting colors are paired up in a corner. Theoretically, you can use the darker contrast colors on the bottom of the panel, but it would imply a light source beneath the TARDIS and it might get wonky.Alternatively, you could achieve the same effect with fabric paints, some sponge brushes, and a lot of patience, but to make absolutely sure you were consistent with your lines you would need to paint your panels before sewing them into the main body anyway, so the quilting is more reliable in my book. No chance of the paint flaking off later, either.