I remembered one of my sidewalk pictures (Flag of an Unknown Country), and composed a watercolor study based on that memory.  I used yellows and yellow-reds in rectangles surrounding a purple triangle. I used the crutch of masking tape to create clean crisp edges of these shapes. I could have anchored my watercolor paper to a drawing board and used a T-square to create a mechanically precise rendering of the stripes but I painted the yellow and purple striations by hand.

I like the gradual deterioration and thinning of the stria as they rise from the wider, more precise belts of color.

Purple Yellow Design
9″x12″ 140# Cold Pressed Watercolor Block