Introduction to Half Square Triangles

As part of our continued dedication to bringing you the best quilting content out there, we’re pleased to bring you this 12-part series from one of our sister sites, McCall’s Quilting. If you missed the prior posts in this series like Pressing Basics, Accurate 1/4″ Inch Seam Allowances, Rotary Cutting Basics, Safety & Maintenance, Basic Quiltmaking Supplies, Quilt Fabric Preperation, Chain Piecing and Opposing Seams, Color Selection Using a Focus Fabric and Simple Fusible Applique – be sure to check them out!


Welcome to our Tuesday Tutorial, where we share a short FREE quilting video lesson each week. Let’s jump right in and learn about one of the most common pieces used in traditional patchwork, the half-square triangle, also known as HST.

Note: please click any image to go directly to the video lesson.

tt HST1 Tuesday Tutorial: Introduction to Half Square TrianglesWhy you’re going to love this technique: HSTs refer specifically to right isosceles triangles, meaning triangles in which two sides of equal length form an interior angle of 90°. When a pattern calls for HSTs, you’ll find that the longest side of each triangle is cut on the bias, which means additional piecing challenges due to bias edges tending to stretch quite easily. Feeling a little frightened at this point?!  Never fear – we’re here to show you the easy-peasy way to make quick work of this common quilting shape!

tt HST Tuesday Tutorial: Introduction to Half Square TrianglesTricia Camp explains and demonstrates how to layer two simple squares together, stitching them in such a way that you’ll end up with two HSTs, without needing to handle the raw bias edges of the patches. You’ll also learn the easy formula for determining what size to cut your squares to end up with the exact HST size your pattern calls for.

Give this easy technique a try the next time your quilting pattern calls for HSTs. Click here to watch the FREE video demonstration of how to make Half-Square Triangles using two squares.

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  1. I need a stain removal advice. I have some antique quilt blocks embroidered by my Mom on white cotton. Some of the blocks have brown stains from being stored in a card board box. Does anyone know how to remove these stains? Thank you.


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