These are straight columns of triple square triangle blocks. The real challenge is getting the right colors to alternate light & dark, changing hues in a "natural" way. Well beyond my current color abilities ~ Colourwave Quilt
Batik Rainbow by Lisa-S Explore #303 I finally decided on a concentric circle pattern. I'm quite pleased with the results. Instead of marking it I cut out circles from freezer paper, ironed them on, and quilted around them. It went quite quickly but is difficult to keep a smooth arc when stopping and starting.