The base lines set the final composition, as they define the precise boundaries of each colored area. Careful attention is paid to how these borders interract with the car's body lines and curvature. Because Deco markers flow by gravity, and the car cannot be turned or flipped like a canvas, linework is a very time consuming process. This is also the step during which I lay out the triangles used to break up large areas and create transitions. Any mistakes were patched with black paint, then white, then clearcoat to seal it. Although afterrward I discovered that paint thinner can be used sparingly to erase the enamel safely over acrylic paint.