Isn’t this a striking quilt block pattern? It has a simple construction but almost looks three dimensional. I love the way that you can create depth just by using colour placement. The quilt block goes by various names but I think that geometric illusion is very appropriate.
Making the geometric illusion quilt block
There are two sizes of half square triangles needed to make this quilt block. Make these by placing two squares with right sides together and marking a line along the diagonal. Sew a 1/4″ seam either side of the marked line and then cut along the line to produce two half square triangles. You will need four 2.7/82 squares each in dark and light fabric and two 4.7/8″ squares in both fabrics.
To make a 16″ quilt block you will also need twenty 2.1/2″ squares in the dark fabric and five 4.1/2″ squares in the light fabric.
Lay the squares out with the small purple squares around the edge, the small half square triangles in the middle of each edge and the white squares forming the cross in the middle. The Nancy Cabot name for this quilt block is white cross which is accurate but not such an interesting name.
Sew the squares together in pairs across the top and bottom rows. Sew the small squares down each side together in pairs so that they can be sewn to the side sof the large squares. Continue sewing all the patches together in rows and then sew the rows together.
That completes the geometric illusion quilt block. I think that this is one of those quilt blocks that would work well either placed side by side or rotated and sewn together in diagonal rows.
You can see the geometric illusion quilt block in a quilt here.