After having such a good time with the X Marks the Improv Block, I chose another simple improv block for Faith Circle for February. Reminiscent of a quarter log cabin block, this one is unique in that it is composed of stripes, finishing at 12 1/2". It is improv though, so it could be easily adapted to any size you want. [Faith Circle, please see our flickr group for more specifics.]
Striped Quarter Log Cabin block
Start by cutting 1 1/2" to 2" wide strips of gray and white fabrics. You can use 14" lengths or cut WOF and trim as you go. Strips would preferable be of angled widths. You'll be building a 'slab' of stripes and then trimming later. Start by sewing a few gray and white pairs together. It would be fine to trim and angle the pairs once they've been pressed.
Piece several strip sets together, inserting one colored (green in photo) stripe.
Once your slab is about 11" x 14", trim so the left side and bottom are at a right angle. Cut two 3" x 14" colored strips for the two 'borders' and sew to your slab, bottom, then to the left. The number of stripes is not critical, as long as the slab comes off as striped. Trim your block to 12 1/2" square. [Note that the fabric dimensions given are generous, so you can easily use scrap strips if you wish.]