The Essential Half-Square Triangle Block

The half-square triangle is one of quilting’s most versatile blocks, but getting them to come out the right size can feel like a constant struggle. This hands-on class changes that! You will learn three different construction methods, understand the pros and cons of each, and discover how to trim your blocks for a perfect finish every time. Master this essential technique and explore the endless design possibilities this one simple block unlocks for your future quilts!

The three methods you’ll learn:

• 2-at-a-Time Method

• 4-at-a-Time Method

• 8-at-a-Time Method

In this class, you’ll also learn:

• The pros and cons of each method so you can choose the right one for any project

• How bias and straight of grain affect your half-square triangles — and why it matters

• How to trim blocks accurately for a consistent, perfect finish every time

• The incredible versatility of this block — illustrated through 18 different quilt layouts made entirely from half-square triangles

You’ll leave with enough half-square triangles to assemble into a small wall hanging using a layout of your own choosing, plus access to six digital reference guides covering all three methods, trimming, layout options, and fabric grain — everything you need to keep making them long after class ends.

This class is perfect for you if:

• You struggle to get half-square triangles to come out the right size

• You want to improve your skills with this everyday block

• You’re not sure how to trim half-square triangles accurately

• You want to see just how much design variety one simple block can create

Supply List: 

• Sewing machine in good working order with power cord, foot pedal, and manual

• Approximately ½ yard of a light fabric and ½ yard of a dark fabric. See Pre-Class Fabric Cutting Instructions below.

• Small cutting mat, minimum 12” on one side

• Rotary cutter, with a new, sharp blade

• 6” x 6” acrylic ruler (or other size square ruler)

• Marking pen/pencil for light and dark fabrics

• Sewing basics: thread, scissors, seam ripper, pins, etc.

• You do not need a specialty half-square triangle trimming ruler but if you have one, bring it to class. Half-square triangle blocks will be trimmed to 4 ½” x 4 ½”. 

Pre-Class Fabric Cutting Instructions:

Please cut fabric prior to class so we can get right to sewing. 

Fabric cutting instructions are to make a scrappy wall hanging using 9 different light fabrics and 9 different dark fabrics. You will need approximately ½ yards total for each the light fabrics and the dark fabrics. Fewer fabrics can be used for this project. In that case, cut the total number of pieces noted below among your fabric choices.  

From the 9 assorted light fabrics, cut the following:

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 1) 

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 2)

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 3)

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 4)

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 5)

• (qty 1) 7 ½” x 7 ½” square (fabric 6)

• (qty 1) 7 ½” x 7 ½” square (fabric 7)

• (qty 1) 10 ½” X 10 ½” square (fabric 8) 

• (qty 1) 10 ½” X 10 ½” square (fabric 9) 

From the 9 assorted dark fabrics, cut the following:

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 1)

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 2)

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 3)

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 4)

• (qty 2) 5 ¼” x 5 ¼” squares (fabric 5)

• (qty 1) 7 ½” x 7 ½” square (fabric 6)

• (qty 1) 7 ½” x 7 ½” square (fabric 7)

• (qty 1) 10 ½” X 10 ½” square (fabric 8) 

• (qty 1) 10 ½” X 10 ½” square (fabric 9)