eo-5 Willow Quilt - Design

The Willow Quilt design will be focus on the detail of willow twigs against a changing background. I want a series of nine blocks with a gradation in color - from dark to light. A foggy morning walk gave me the idea:

The density of the plant matter changes as the willow branches out. Also, the background is darker near the bottom of the image. 

I hope to create a windowpane effect, with each block surrounded by a white frame. The block size should be approximately 8.5" x 9.5" with a 6" border between each. The final quilt would then be approximately 44"x 47".

Each block will be paper pieced with a different design. I plan to draw the design on newsprint and then trace onto tracing paper. I don't plan to ever make this quilt again, so I do not want to use a CAD program to create the template. In a way, this makes the project a weird combination of art (one-of-a-kind) and craft (paint-by-number!).