How to Sew a Card Trick Quilt Block

By: Elaine Huff

Ready to add a touch of illusion to your next quilt? The Card Trick quilt block is a traditional favorite that plays with color and geometry to create the illusion of interwoven cards. Perfect for confident beginners, this 12-inch block combines classic techniques like half-square triangles and hourglass patches to achieve its striking design. With just four fabrics and a background, you’ll love how this block comes together with a balance of precision and simplicity. Let’s dive into the step-by-step process to create this timeless quilt block!

card trick quilt block

Fabric Requirements for a 12" Finished Card Trick Quilt Block:

These fabric requirements will make four Card Trick blocks:
  • Background: 4 - 5.5" squares, and 8 - 5" squares
  • Green: 2 - 5.5" squares, 1 - 5.25" square, and 2 - 5" squares
  • Pink: 2 - 5.5" squares, 1 - 5.25" square, and 2 - 5" squares
  • Red: 2 - 5.5" squares, 1 - 5.25" square, and 2 - 5" squares
  • Black: 2 - 5.5" squares, 1 - 5.25" square, and 2 - 5" squares
card trick fabric requirements

Sewing Directions:

Hourglass Unit:

Step 1:

Using one 5.5" square of EACH of the colors (Green, Pink, Red, and Black), sew together four Hourglass units.
  • In the picture below you can see that I paired up the Pink and Red squares and the Green and Black squares.
  • Draw a diagonal line from corner to corner on the back of one of the paired up fabrics.
  • Sew 1/4" on each side of the marked line.
  • Cut along the marked line.
card trick 1
 

Step 2:

Open up the units and press the seam allowances toward the darker fabric as shown in the picture below.
 
 

Step 3:

  • Draw a line on the back of the Pink/Red units, perpendicular to the seam line.
  • Match up each of the Pink/Red units with a Green/Black unit, rotating as necessary so that the seam allowances nest together.
  • Stitch 1/4" on each side of the marked line.
  • Cut along the marked line.
 
 

Step 4:

As shown in the picture below you will have made four Hourglass units.
Press the seam allowance to one side and square up/trim the units to 4.5" square. Notice that two of the units are mirror images of the other two. You only need one Hourglass unit per block so set aside three of the units until making the additional blocks.
 
I found it helpful to make a separate pile of the mirror image units. Keeping everything organized will keep you from getting confused with the coloring of the block.
 
 
 

Half Square Triangle Units:

Step 5:

Using the eight Background 5" squares and the eight Green, Pink, Red and Black 5" squares, make Half Square Triangle units as shown. Press the seam allowances away from the Background fabric. Trim/square up the units to 4.5" square.
 
You will have 16 units but you only need one of each color per block. Set the other 12 units aside until sewing the additional blocks.
 
You can find a detailed tutorial for sewing Half Square Triangles (HST) at https://fabric406.com/blogs/fabric406-blog/how-to-sew-a-basic-half-square-triangle-block 
 
card trick 5
 

Middle Units:

Step 6:

Using the four Background 5.5" squares and the remaining four colored fabric 5.5" squares, sew together eight Half Square Triangles (HST) like you did in Step 5 above. Press the seam allowances toward the Background fabric. DO NOT trim/square up the units. You only need one of each coloring for each block so set aside the other four units.
 
card trick 6
 

Step 7:

Using the pictures in Steps 9 and 10 for reference, match up each of the Step 6 units with its corresponding 5.25" square. For my block I will match up:
  • a Background/Pink HST with a Black 5.25" square.
  • a Background/Red HST with a Pink 5.25" square,
  • a Background/Green HST with a Red 5.25" square, and
  • a Background/Black HST wih a Green 5.25 square.
The HSTs and squares probably won't be exactly the same size but that's okay as we'll be trimming them up later.
 
Draw a line from corner to corner, perpendicular to the seam line of the HST unit. Sew 1/4" on each side of the drawn line and then cut along the drawn line.
 
card trick 7
 

Step 8:

Open up the units, press the seam allowance away from the larger triangle, and trim/square up the units to 4.5" square. In the picture below, you can see that the two Pink/Red units are mirror images of each other. 
 
card trick 8
 

Step 9:

Pick out four units (one of each coloring) that have the large triangle in the bottom left corner and the small Background triangle at the top like shown in the picture below. Set the other units aside for the additional blocks.
 
card trick 9
 

Putting It All Together:

Step 10:

Lay out the Hourglass unit, the four Half Square Triangle units, and the four Middle units as shown in the picture below. 
 
card trick 10
 

Step 11:

Sew the units into three rows as shown in the picture below.  From here the block goes together like a basic Nine Patch block.
 
card trick 11
 

Step 12:

Press the seam allowances toward the Middle units as shown below.
 
card trick 12
 

Step 13:

To complete the block sew the three rows together and...
 
card trick 13
 

Step 14:

Press the seam allowances away from the center of the block. All done!
 
card trick 14
 

Other 3 Blocks:

You will have made enough units to complete another block just like the Step 13 completed block. 
 
You also will have enough of the mirror image units to make two additional blocks like the one in the picture below.
 
card trick 16
 
Here is a picture showing them side by side so you can more easily see the difference.
 
card trick 17
 

Conclusion:

I love the Card Trick block! However, I did have a hard time keeping my extra units sorted properly! And making sure to get the right color combination on the Middle units!
 
The tutorials I found online for the Card Trick block have you cut all the triangles and then sew on the bias. I prefer to make my triangles using squares and cutting apart after sewing. So while it was confusing (and took awhile) for the first block, in the end I had all the units done to make three more blocks. That was nice!
 

I hope you have enjoyed this tutorial. If you like it and want to see more, just click HERE to sign up for my newsletter and receive a free PDF quilt pattern called "Chained Weathervane".

Happy Quilting!

Elaine

P.S. Looking for scrappy blocks? Check out this blog post by clicking on this link: https://fabric406.com/blogs/fabric406-blog/40-of-the-best-free-scrappy-quilt-block-tutorials

P.P.S. Check out my Etsy shop at https://www.etsy.com/shop/fabric406