Pinwheel blocks are a fun way to add some pizazz to your quilting creations. They can be used as an accent block amid other block types, or they can be used for an entire quilt, as they are in my quilt pattern Pinwheel Parade. This tutorial will walk you through the steps to making a Pinwheel block.
Half Square Triangles
Pinwheel blocks are made up of four half square triangles (HST). There are many methods to make HST's, but for the purposes of this tutorial we will focus on the two-at-a-time method. For a more in depth tutorial on HST's, please see my tutorial How to Easily Make Half Square Triangles - Three Simple Methods.
We will be making an 8" finished Pinwheel block. For this, you will need four 4.5" finished (after trimming) HST's.
You will need 2 - 5" focus fabric squares and 2 - 5" background fabric squares.
Place a 5" background square on top of a 5" focus fabric square, right sides together. Using a ruler and pencil, draw a diagonal line across the top (background) square. It is helpful to use a dab of fabric glue at the corners or pins to hold the squares together while you mark.
Sew a line ¼" on each side of the drawn center line. Press the blocks flat, this serves to set in the seam lines, helping them to lay flat when you press them open.
Cut along the center diagonal line, making two triangles.
Press open the triangles, pressing the seam toward the darker fabric. Use care not to stretch the bias edges.
Use a square ruler to trim the block to 4½" square.
Completing the Block
Lay out your block as shown below.
Sew the top two blocks together. Then sew the bottom two blocks together. Press the seams in alternating directions.
Sew the top and bottom sections together to complete the Pinwheel block.
Pressing Pinwheel Blocks
After the top and bottom sections are sewn together, there will be a lot of bulk in the center where all the HST’s meet. This is not ideal for many reasons! This bulk may distort the blocks, altering the appearance of the blocks. It may cause thread breakage when you try to quilt through the block as well. To remedy this, press this last joining seam (where you have sewn the top and bottom sections together) in alternating directions. (On one side of the center, the seam would be pressed up, on the other side of the center, the seam would be pressed down.) As you do this, use a stiletto or your finger to carefully pull the edge of the center joined seams away from each other, like fanning them out.
This will create a little mini-pinwheel at the center intersection point as shown below. Press the block well from both sides and your Pinwheel block will lay flat.
Pinwheel blocks lend themselves to scrap fabrics very well, making them an excellent scrap-buster project. They can be elegant or casual, depending on the fabric and block setting used. They are also a good way to use up any left over HST's you have lying around from other projects!
I hope you have found this tutorial helpful!
Happy Quilting!
