Diamond quilt borders can add a really special look to your quilt. The diamonds can be made using squares or rectangles but I am only looking at squares here.
Make the triangles
The entire diamond quilt border is made using 4.1/2″ squares in green fabric, 4.7/8″ squares in light fabric cut in half to make triangles and 5.1/4″ squares in light fabric cut into four triangles. This makes a basic unit 6″ long – 5.1/2″ finished size.
Basic unit of diamond quilt border
The basic unit of the diamond quilt border is a green square with a half triangle square on each side. Do check which way you place the triangles – it’s easy to get it wrong. Sew the right triangle of the lower unit to the square of the unit above so that the square of the lower unit is sewn to the left hand triangle of the unit above.
I puzzled for a while over how to piece the corner of the diamond quilt border without any inset seams and finally came up with a way that works well.
For the part of the diamond quilt border running up the right hand side of the quilt top, finish with a gree square that has a half square triangle on the left hand side but not on the right hand side. Sew a quarter square triangle to the top left hand side of the green square.
Cornerstone for diamond quilt border
Make a corner unit for the diamond quilt border using a green square with a quarter square triangle on top and half square triangle on either side. These half square triangles are not attached the same way as in the basic diamond quilt border units, so do check the photo.
Sew the quilt border along the right hand edge of the quilt top first. The diamond quilt border along the top is just several of the basic units. Sew it to the top edge of the quilt as shown with the end of the top border unit lined up with the edge of the quarter square triangle of the right hand border. this gives you a straight edge across the diagonal of the corner. Sew the corner unit to this edge.
I haven’t given numbers of squares to use in the diamond quilt border because obviously it depends on the size of your quilt, but you can make sure that the quilt top is the right size to take an exact number of border units by varying the width of the first border strip – I have sewn a 3.1/2″ strip of green fabric either side of the diamond border and it is this strip that can be varied in width. I find this easier than trying to work out what size to make the border units to fit a different size quilt.