The Lady of the Lake quilt block pattern is traditionally made with two fabrics and looks lovely with a solid or small print fabric with scraps for the second fabric. It is made from two sizes of half-square triangles, also known as HSTs. For more information about HSTs, we’ve got a great article that has seven (7) ways to make HSTs.
What is a Lady of the Lake quilt block?
A traditional quilt block made entirely from two sizes of half-square triangles.
Is it beginner friendly?
Yes. If you can make accurate half-square triangles, you can make this block.
What size does it finish?
I’ve included cutting measurements for 5″, 10″, 15″, and 20″ squares.
How many fabrics do I need?
Two fabrics, or one background plus scraps.
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Quick start
Skill level: Beginner to confident beginner
Time: About 35 minutes per block
Techniques:
- Half-square triangles
- Accurate trimming
- Chain piecing
- Pressing
Great for:
- Scrap quilts
- Two-color quilts
- Sampler quilts
- Learning HST accuracy
What you’ll learn
In this tutorial you’ll learn:
- how to make two sizes of half-square triangles
- how to trim HSTs accurately
- how to keep the block orientation correct
- how to assemble the sawtooth rows
- how to avoid losing your points
- how to use the block in larger quilts
RELATED: Sawtooth Star Quilt Block
EXPLORE: More half square triangle quilt block patterns
Why quilters love this block
- only two fabrics
- wonderful scrap quilt
- dramatic secondary patterns
- perfect practice for HSTs
- traditional block dating to the 1800s
For this tutorial, I used two solid fabrics to make it easier for you to see the steps to make the Lady of the Lake block. Here is the basic block:
As you can see, this quilt block is made from two sizes of half-square triangles. If you want to get lots of practice making half-square triangles, this is a perfect block for you.
Here are cutting directions for the Lady of the Lake quilt block in four sizes:
Here are step-by-step instructions for making a single block the Lady of the Lake quilt block:
How to Make the Lady of the Lake Quilt Block
Learn how to make the Lady of the Lake quilt block with these step-by-step directions. The block has one large half-square triangle surrounded by sixteen (16) smaller half-square triangles.
Materials
- Fat quarter or 1/4 yard each of two fabrics. For a scrappy look, select one solid fabric and use scraps of prints for the second fabric.
- Coordinating thread for sewing
Tools
- Sewing machine
- Iron
- Pressing surface or ironing board
- Removable fabric marker
Instructions
Step 1: Cut fabrics
Start by cutting squares as outlined above for the finished size quilt block you'd like. I made 10-inch finished quilt blocks, so cut my smaller squares at 2-7/8 inch and the larger square at 6-7/8 inch.
Step 2: Mark fabrics
To make the half square triangles, refer to our article on 7 ways to make half-square triangles.
I've chosen to make them two-at-a-time. I find that my preferred method. Begin my marking a diagonal line on the wrong side of one of the fabrics with a removable fabric marker. I used a Frixion pen that comes out with the heat of an iron. 
Here is my pile of squares with the diagonal lines drawn. 
Step 3: Sew diagonal lines
Take one of each of the squares and layer them two with right sides together, with the marked diagonal line up. Begin sewing 1/4-inch from one side of the drawn line.
TIP: Sew them in the "chain method" to make it quicker. 
When they are all sewn, turn the 'chain' around and sew 1/4 inch from the other side of the draw line. 
When you have completed sewing on both sides of the marked line on the smaller squares, then do the same on the large square. 
Step 4: Cut along marked line
Cut along the drawn line to make the half-square triangle. 
I made four finished Lady of the Lake quilt blocks. Here are my blocks all cut apart and ready for pressing.
Step 5: Press
Press the seam to your preference. I like to press this seam open. For more information on pressing seams, see our article with tips for pressing seams in quilting. 
Step 6: Trim
Take the time to trim the pressed blocks. This is worth the time. Trim off the 'dog ears' (the triangle ends at the diagonal seam) and make sure that the block measures exactly 2-1/2 inches (or whatever the finished half square triangle size should be). 
Step 7: Sew blocks together
Now we're ready to start sewing together the sides made from the smaller half-square triangles. These are sometimes referred to as the 'sawtooth rows'. You can see I'll want two sets of three (3) HSTs, and two sets of five (5) HSTs to finish the quilt block.
I started by sewing sixteen (16) sets of two of the smaller triangle-squares with right sides together and a 1/4-inch seam allowance. Then, I took six (6) of the sets and added one half square triangle to make them sets of three (3) for the side units. Be careful on the positioning of the light and dark fabrics! Follow the quilt block layout! (Ask me how I know! I did some unsewing!) 
Next, sew two sets of two (2) half square triangles together to make strips of four (4) half square triangles. 
Then, add the fifth half square triangle for the top and bottom strips. 
Press the seams. Then lay out the strips with the center larger half square triangle. Oops - I need to do some unsewing! 
Here is a correct layout for sewing the strips to the center.
Sew the sides to the center first. Press the seams.
Sew the top and bottom strips to the quilt block.
Step 8: Enjoy your finished blocks!
Here are four finished blocks sewn together. 
Have fun with different layouts for the Lady of the Lady quilt block. Here is a 4 x 4 layout:
How did this block get its name?
I did a little research on the legend of King Arthur and the Lady of the Lake. According to Arthurian legends, the Lady of the Lake was an enchantress of the lake around Avalon. She is famous for giving King Arthur the magical sword, Excalibur. Maybe all of the sharp edges on this quilt block depict the edges on the magical sword? Who knows – but it’s a good story!
Common mistakes
Block won’t finish square > Usually seam allowance isn’t a true quarter inch.
Points don’t match > Trim every HST before assembling.
Layout looks wrong > Lay everything out before sewing. Take a picture with your phone. Refer back to your picture each step.
Corners disappear > Don’t over-trim after sewing rows together.
Ideas for making Lady of the Lake blocks:
Try different fabric combinations! Solid colors, try one of the fabrics as an ombre for a different effect. If you are using prints, try using one with a large print and one with a small print. Fabric ideas include:
- solids
- reproduction fabrics
- florals
- batiks
- low volume backgrounds
- holiday prints
- denim and linen
Natural white fabric helps set off the other fabric. Organic linen can be used for a natural look.
These beautiful blocks are fun to make and perfect for intermediate quilters who are ready to perfect their HSTs.
Quilting ideas
- straight line quilting
- diagonal grids
- echo quilting
- crosshatch
- all-over meander
- walking foot lines
Frequently asked questions
The Lady of the Lake is a traditional quilt block made from half-square triangles (HSTs). It creates a striking geometric design with just two fabrics, making it a favorite for both traditional and modern quilts. When several blocks are sewn together, they create beautiful secondary patterns across the quilt top.
Yes! If you’ve made half-square triangles before, this is a great beginner quilt block. The construction is straightforward, and there are no curved seams or complicated piecing techniques. Taking the time to trim your half-square triangles accurately will help your finished block come together perfectly.
This tutorial includes instructions for 5″, 10″, 15″, and 20″ finished block size. Once you’ve mastered the construction, you can easily resize the block by changing the size of your half-square triangles.
You only need two fabrics to make a classic Lady of the Lake block: one light fabric and one dark fabric. It’s also a wonderful scrap quilt block, so don’t be afraid to mix several coordinating prints for either the light or dark sections.
Absolutely! The Lady of the Lake block is perfect for using leftover quilting fabric. Choose scraps with enough contrast so the design stands out. You can use a single, consistent background fabric with a variety of colorful prints, or make each block unique by using different fabric combinations.
Points are usually lost when the seam allowance is slightly larger than a true quarter inch or when the half-square triangles weren’t trimmed accurately. Double-check your seam allowance, trim every HST to the correct size, and avoid stretching the fabric while sewing and pressing.
Either method works, and many quilters have a personal preference. Pressing to one side helps the seams “nest” together, making matching points easier. Pressing seams open can reduce bulk, especially if you’re using thicker fabrics. Choose the method that gives you the flattest, most accurate block.
You may enjoy: How to Press Seams in Quilting
The secret is to sew with an accurate quarter-inch seam allowance, press carefully without stretching the fabric, and trim every half-square triangle to the exact unfinished size before assembling the block. Even small differences in size can add up and affect the finished block.
Yes! You can use any half-square triangle method you like, including the two-at-a-time, four-at-a-time, or eight-at-a-time methods. Simply make the number of HSTs needed for the block and trim them to the correct unfinished size before sewing the block together.
The Lady of the Lake quilt block proves that simple shapes can create dramatic quilts. Whether you sew one block for a sampler quilt or dozens for a full-size quilt, this classic design is a wonderful way to practice accurate half-square triangles while creating something timeless. Once you’ve mastered this block, try experimenting with different color placements to create entirely new quilt layouts.
Related traditional quilt blocks:
- Swamp Angel quilt block
- Duck Tracks quilt block
- Road to California quilt block
- Irish Chain quilt
- Ohio Star quilt block
- Ribbon Star quilt block
Browse through more free half-square triangle quilt patterns on Create Whimsy.
