Sew your strips into 4 sets ( cut your full width strips in half) with all the strips lined up the same. Separate into 2 sets (Fig 1) - one a mirror image of the other. Press one set with all seams toward the #2 strips and the other sets toward the #7 strips.
Next stack the 4 sets on top of each other with all the strips in alignment. Cut the stack into 2 ½” sections. (Fig 2). If you have a strip cutter this is the perfect place to use it.
Now you will separate the strips into 2 piles. One pile will have the seams pressed toward the top and the second will have them pressed toward the bottom. Fig 3 The easiest way to do this is to pick up the stack of 4 strips - lay the first 2 to the right and the next 2 to the left.
Now you will start building your first blocks. Get out that seam ripper!
You will start with a full strip - placed in the center. The next strips 2 & 3 you will remove the first square. Set the removed squares off to the side you will use them later. When you are picking up your strips to add to each side alternate between the 2 piles you made when you were separating them (Fig 3). I flip up a strip on the pile that I will be using next. You do this so that you have opposing seams. Continue in this manner, removing one more square each time, until you have only one square on each end.
Sew your ½ block - starting with the single square on the far left and then add a strip until have added all of the strips and you have a triangle. This is the first half of block 1.
Take the squares that you removed from the strips in block one and arrange them in the same manner. Your ½ block will not be as large as the first by one row. This will be the second half of block 2!
Flip your stacks of strips over and start building the next parts of your blocks. This time you will start with the opposite end of the strips - strip #8. Continue until you have the opposite sides of the blocks. You will have extra strips that you may need to use in order to get your last 2 single squares.
Sew the 2 halves down the center and you have completed 2 approximately 18” blocks from you strips sets.