This pretty, classic quilt block isn't as tricky as you might think! Sew up a card trick quilt block with this tutorial for a 12½" unfinished quilt block (12" finished). You can use large fabric scraps that play well together, like solids or small-scale prints.
How to sew a card trick quilt block
What you need:
Choose 4 colors for your cards and one color for your background fabric.
- A 5¼" square from each of the card fabrics and the background fabric.
- A 4-7/8" square from each of the card fabrics
- Two 4-7/8" squares of the background fabric
Cut each of the larger 5¼" fabric squares twice diagonally so they are quarter-square triangles. You can stack two or three at a time to make these cuts.
Cut all of the smaller 4-7/8" fabric squares once diagonally into half-square triangles.
These are the quarter-square triangles (left) and the half-square triangles (right).
Set aside 2 of each color of the quarter-square triangles (except the backgrounds, of which you'll use all). You won't need them for this block.
Arrange the half- and quarter-square triangles as pictured above:
- Starting in the center, arrange four different quarter-square triangles into an hourglass unit.
- Match the corner HST units to the card color in the middle, and arrange with the background fabric facing outward.
- Arrange the other so the card colors match the middle and corner units in half- and quarter-square triangle units.
Refer back to this picture (or take your own photo with your phone) as you sew your block, to help you keep all of the pieces straight.
First, sew the center unit together.
Using a scant ¼" seam allowance, stitch two quarter-square triangles along the short ends. Repeat with the other pair of triangles. Then, with right sides facing, stitch the triangle pairs along the long ends, being sure to match up the center seams.
Press the seams all to the right, as pictured, so the center lays flat (pictured above).
Trim this block unit to a 4½" square. To do this, you can use a sticky note or tape on your ruler to mark the 2¼" line, and make sure this lines up with the center of your hourglass block when trimming each side.
Chain piece all of the adjacent quarter-square triangles along the short sides. Press the seams toward the darker fabric, and return them to the layout.
This is the card trick block layout with all of the quarter-square triangles joined, including the center hourglass unit.
Next, grab all of the half-square triangle pairs and pin them together along the longest side. Take them to the sewing machine.
Chain stitch the half-square triangle pairs together using a scant ¼" seam allowance. Some of these will include the quarter-square triangle pairs you already joined.
Press the seams on the triangle units toward the darker fabric. When pressing a unit with multiple seams, press away from the side with more seams.
Trim each of the block units to 4½" square. Lining up the triangle's seam with a 45-degree angle on your ruler is helpful for this step.
Return all of the block units to your layout. Next, join the three units in each row, making sure to pin the blocks at the seams! Repeat with the other two rows.
Alternate the direction you press the seams on each row. On the top and bottom rows, press the seams out. On the center row, press the seams in. This will help your block lay flatter.
Finally, pin together the rows of the card trick block and stitch them together with a scant ¼" seam allowance. Press the final seams out toward the block's raw edges, and trim any stray threads off the 12½" square block.
Isn't it a fun optical illusion? I hope you've enjoyed this card trick quilt block tutorial and that you'll add it to your library of traditional quilt blocks!