Quilts · Tutorials

Making Half-Square Triangle Blocks


  • Place two 2.25″ squares with right sides together (one white and one buff)
  • Draw a light pencil line diagonally across the wrong side of the white square.
  • Sew a scant 1/4″ seam next to the pencil line. I was able to use the side of my presser-foot as a guide.
  • Turn the block around and sew another scant 1/4″ seam next to the other side of the pencil line. Sewing from one block onto the next block, in a chain-like fashion, speeds this process up.
  • Cut along the pencil lines
  • Iron seams to dark side (LOL – I like saying that)
  • This creates two half-square-triangle blocks.
  • To make the white/white blocks, use two 2.25″ squares of white
  • Square-up* each 1/2 square triangle block.

How to Square-up the Half-Square-Triangles


Carefully place the block on cutting mat, with the diagonal seam on a diagonal cutting guideline and centered over 4 one inch blocks.
Place a clear ruler on top of the block, being careful not to shift it at all.
Hold the ruler firmly in place. Use a rotary cutter to cut off the edge of the block that sticks out from under the ruler.
Pick up the ruler and place it on another side. Again, being careful not to shift the block. Cut off the excess with the rotary cutter. Go around the block cutting each side.
All squared up!! 🙂