Here's my completed pillow.
You will need:
1/4 yard of your two colors (pink and green) or 1/2 yard of one color for a monochromatic argyle
1/2 yard of your white for the rest of the diamonds
1/2 yard of backing fabric
1/4 yard for the "sashing" (the brown- I'm calling it sashing for lack of a better term)
16 inch pillow
Spray starch - I'm not usually a big starch user, but it's helpful to starch all your fabrics with all the sharp points in this one.
Start by cutting your diamonds.
Cut two 3.5 strips for each color and four 3.5 strips for the white.
Once it is laid out, you will piece together the dimonds in rows in the direction indicated by my wonky arrow.
Draw a quarter inch line on the piece you are working on.
Line the quarter inch mark on the green piece so that it lines up with the edge of the piece beneath it. (Where the arrow is pointing). It should form a nice "V".
Once your rows are put together, you will need to join them. To line up your points, match the quarter inch line so it intersects with the color going in the opposite direction beneath it. In the photo above take a look at the left pin. You can see the green fabric underneath meeting the quarter inch line above to make a "V".
Once all your lines are sewing together you can cut your sashing at 3/4 of an inch.
Measure the halfway mark for your diamond width and cut. This should be 1.5 inches. Then you can start attaching the sashing.
I've had to jump ahead a little in my photos to demonstrate the best way to line up your diamonds. I was this far in when I figured it out! Up until this point I had been eyeballing it and doing some seam ripping. What I learned was this: Attach the sashing to one side of the cut. Then line up the other side of the strip overtop of the new sashing so the sashing lines meet up (or the diamond tops and bottoms). You can see this above on the line where the arrow points.
Flip the row over where it stands.
Then shift it to the left over to the edge of the sashing where you will pin it without shifting it up or down.
Continue until you have both directions completed.
Trim to 17 x 17. At this point I debated adding fusible web for stability. This is totally your call. I chose not to add it.
Cut your backing fabric into two pieces. One should be 17x14 and the other 17x10. On both pieces, take one of the 17 inch length sides and fold it in 1/2 inch and press. Fold in it another 1/2 inch and press again. This will keep the edges nice.
Placing fabrics right side together, lay down the large piece first. Make sure the folded edge is face up and line up your edges.
Lay the second piece on top and pin everything carefully. Sew around with a 1/4 inch seam and back stitch over the folded section for stability. Finish your edges as you like. I found with so many layers of fabric I couldn't use my pinking shears. I don't have a serger so I zigzag stitched around the edge.
Place the cover on your pillow and you are done! Hope you like it.