This is a pieced sashing that looks a little challenging–but don’t be alarmed! I’ve broken it down enough to be easier than it appears.
That being said, I would encourage you to begin by making one at a time and then measuring the sashing to be sure it is exactly the same size. You may have to make a slight adjustment depending on the accuracy of your 1/4″ seams as well as the nature of the fabric you are using. I’m using Kona cotton and I found that when I sprayed starch on the final sashing block and pressed it, it became a little bit longer–which ended up being the exact size that I needed.
Decide which color you want to be your large diamonds and which you want to be your small diamonds. My small diamonds will be the same color as the cornerstones we will make in the next step.
Begin by cutting the following pieces:
Eleven strips 3 3/4″ x WOF
Four strips 2 1/4″ x WOF
Four strips 4 1/2″ x WOF
Subcut into thirty-one (31) 4 1/2″ squares
Cut squares in half diagonally.
Four strips 4 1/2″ x WOF
Do not subcut these yet.
Color 1 (small diamonds)
Four strips 1 15/16″ x WOF
Color 2 (large diamonds)
Five strips 2 5/8″ x WOF
Using Three of the 1 15/16″ x WOF (color 1) strips and six of the 3 3/4″ x WOF strips and make three strip sets with the color strip in the center. Press toward the center fabric.
Make four strip sets using four of the (color 2) 2 5/8″ x WOF strips, four of the 2 1/4″ neutral strips and four of the 3 3/4″ neutral strips. Press toward the center fabric.
You will have one 3 3/4″ x WOF neutral strip, and one of each of the color strips (one 1 15/16″ x WOF and one 2 5/8″ x WOF)
Cut the remaining neutral strip in four approximately equal pieces. Cut each of the color strips approximately the same length. Use these pieces to make two mini strip sets to match the previous strip sets. (The 2 5/8″ strip set will have a bigger piece of neutral on one side, but it will eventually be cut off.)
Cut across the strip sets to make the individual pieces. Cut each of the 2 5/8″ strip sets into fifteen 2 5/8″ pieces. Cut two more pieces from the mini strip set.
Cut each of the 1 15/16″ strip sets into twenty 1 15/16″ pieces. Cut two more pieces from the mini strip set.
In total you should have 62 of each of these pieces.
Sew one of each of the above pieces to each other matching seams as shown below. Make 62 of these.
Using one of the 4 1/2″ uncut strips, cut one end off at a 45 degree angle as shown below.
Cut ONE 3 1/8″ angled piece from this strip. (Remember we are making just one sashing unit until we know it is the correct size.)
We now need to find the center of this piece. Here is my method.
Cut one strip of freezer paper with your rotary cutter and ruler. Cut it approximately 1 1/2″ wide, but be sure it is absolutely straight. Press this piece to your ironing board.
Lay one of the shorter edges directly next to the freezer paper.
Now fold over so the other end is also directly next to the freezer paper.
Here is a picture with a different fabric that makes it easier to see.
Using your favorite disappearing marker draw a short line across the fold and 1/4″ away from the edge of the fabric.
I also like to slightly mark the fold line inside the seam allowance.
Lay out your pieces as shown below.
Each of the corners of the small diamonds will match the mark I just made.
Trim this unit to 4 1/2″ wide with the intersections along the 2 1/4″ mark on your ruler.
Here is a close up.
Your piece should look like this.
Sew two of the neutral triangle pieces on each end as shown.
You can eyeball the placement of the triangle. You must make sure the triangle goes above the cut edge on the side above the larger diamond. The other side will be cut off so it doesn’t need to be even.
Now measure the blocks that you have already made over the past couple of months.
Measure from the outer tips of both of the large diamonds. This should be 1/2″ less than the size of your blocks. If it isn’t, cut your next diagonal piece a little smaller or a little larger.
Trim both ends so both ends extend 1/4″ away from the tip of the large diamond. Use the 45 degree marking for accuracy.
Trim the sides of the added triangles so they are even with the rest of the block.
Finally measure the block again to be sure it is 4 1/2″ x the width of your blocks. (Mine are 14 1/2″)
If your measurement is correct cut the remaining diagonal pieces and make 30 more of these units. You will need 31 sashing pieces.