The HST, or Half Square Triangle, is an essential building block used in many traditional quilt designs. We love to make a bunch and have fun arranging them in our favorite designs! This Sewing 101 is perfect for both traditional and modern quilters – and instructions are given for 5” finished squares.
Free Quilt Block Tutorial
2 quilting fabrics of your choice. Traditionally you would choose one printed fabric or a solid color, and one white or neutral fabric.
Acrylic Rulers (6.5" square size and a longer ruler for marking)
Method 1: Traditional Method/2 HST’s
This method is perfect if you’re working with scraps and don’t have large pieces to try the methods that make more. Each square makes two HST’s.
Cut (1) 6” square from each fabric.
Mark a diagonal line with your marking pen on one fabric square (it can even be a permanent pen or pencil, this line won’t show on your finished blocks.
With your two squares placed on top of each other, sew a scant ¼” on each side, remember to backstitch!
Cut in between these two sewn lines. Press towards the darker fabric. Trim if needed.
Method 2: Four at a Time HST’s
This method is great because you don’t have to draw any lines at all, which is perfect for a ¼ yard piece of fabric! You’ll be able to get 16 5” square out of an 8.5” strip cut into 4 8.5” squares.
Cut (1) 8.5” square from each fabric.
Placing one square on the other, sew along the edges at ¼”, pivoting at the corners.
Cut in an X formation, corner to corner. Press towards the darker fabric – now you have 4 HST’s!
Method 3: 8 at a Time HST’s
This method is great for yardage, and it’s super easy to cut if you have a 12.5” square ruler.
Cut (1) 12.5” square out of 2 fabrics.
Place one fabric on top of the other. Mark diagonal lines in an X formation. Sew at a scant ¼” on either side of your marked lines. Make sure your fabric stays in place and doesn’t bunch when you sew over existing lines.
Cut your fabric in a cross formation, even in the middle on all sides. Then, cut between seams.
Press your triangles towards the darker fabric. Trim if necessary. Now you have 8 HST’s.
Method 4: Strip HST’s
This method is great if you have an eighth of a yard, a quarter of a yard, or even jelly rolls for itty bitty HST’s. This one is tricky and takes some very precise cutting.
Cut (1) 4.5” strip of each fabric by however long you want. If you want a lot, cut by WOF (Width of Fabric).
Sew your two strips along the long edges at ¼” seam allowance.
Using your square ruler, place your ruler as demonstrated in the video. The tip of the square should just touch the top seam. Cut on each side. For the next HST, you will flip your ruler so the point is in the opposite direction, but will only have to cut one side.
Keep cutting until you run out of strip to cut from.
Happy HST making!