The finished backing:
Creating the fabric triangles (2"x 1"). The fabric triangles have to be the same on both sides (right sides showing) so I had to cut 2" fabric strips, then a 2" strip of double-sided fusible web, followed by another 2" wide fabric strip. I put the fusible web on the wrong side of one fabric strip, layed the wrong side of the other on top, and fused both pieces of fabric together:
Off to cutting the 2" x 1" fabric triangles with my rotary mat/cutter/ruler.
...followed by pressing one side of the triangle in towards the center, then the other so it looks like the samples on the right:
At this point I'm at the pic below, playing around with triangle colors and my design. The off-white linen is too "white", so right now I'm dying the linen triangles and linen fabric in tea, hoping for a darker off-white color. Unfortunately, all I have are green tea bags and no black tea ones. So I'm not sure if the color will be dark enough. Another tea bag session may be in the works.
The center area I'll probably secure with hand stitching, the radiating lines of triangles will probably be affixed with fabric adhesive. Off to check my tea-dyed linen right now.