Traditional pattern, public domain. Widely published in early 20th-century quilting periodicals.
An intriguing optical illusion block that uses four overlapping 'cards' created from half-square triangles and quarter-square triangles. Each card appears to tuck behind the next, producing a three-dimensional woven effect from flat fabric.
The Card Trick block became popular in the early 1900s during a period when quilters were fascinated by optical illusion and dimensional designs. It was widely published in newspapers, farm journals, and pattern booklets of the 1920s-1940s.
Card Trick reflects the American quilting tradition of creating complex visual effects from simple geometric units. The block's name evokes parlor entertainment — card games and magic tricks were popular pastimes. Quilters prized this block for its apparent complexity despite using only triangles and squares.
Also known as: Friendship Block, Japanese Friendship Block
finished Block Size
12 inches
seam Allowance
1/4 inch
grid Basis
3x3 grid (each unit 4 inches finished)
units Required
4 quarter-square triangle units, 4 half-square triangle units, 1 center square
All measurements include 1/4" seam allowance unless noted.
| Piece | Fabric | Cut Size | Qty | Notes |
|---|---|---|---|---|
| A | Fabric 1 (purple) | 5 1/4 x 5 1/4 inches | 1 | Cut twice diagonally (X) for quarter-square triangles |
| A | Fabric 2 (gold) | 5 1/4 x 5 1/4 inches | 1 | Cut twice diagonally (X) for quarter-square triangles |
| A | Fabric 3 (green) | 5 1/4 x 5 1/4 inches | 1 | Cut twice diagonally (X) for quarter-square triangles |
| A | Fabric 4 (rust) | 5 1/4 x 5 1/4 inches | 1 | Cut twice diagonally (X) for quarter-square triangles |
| B | Background | 5 1/4 x 5 1/4 inches | 2 | Cut twice diagonally (X) for quarter-square triangles |
| C | Background | 4 7/8 x 4 7/8 inches | 2 | Cut once diagonally for corner HSTs |
| C | Fabric 1 (purple) | 4 7/8 x 4 7/8 inches | 1 | Cut once diagonally |
| C | Fabric 3 (green) | 4 7/8 x 4 7/8 inches | 1 | Cut once diagonally |
| D | Background | 4 1/2 x 4 1/2 inches | 1 | Center square |
Pair each colored quarter-triangle with a background quarter-triangle to make half-units. Then combine two half-units to form a quarter-square triangle square that shows two adjacent colored 'card tips' with background fill. Each QST unit should measure 4 1/2 inches. Make 4 QST units, each with a different color combination.
Tip: Mark the sewing line on the bias edges and pin carefully — these are all bias edges and will stretch easily.
Pair each colored 4 7/8 inch triangle with a background triangle. Sew along the long edge with a 1/4 inch seam. Press toward the dark fabric and trim to 4 1/2 inches square. Make 4 corner HST units (2 from each color pair).
Tip: Use a dab of starch on bias edges before sewing to stabilize the fabric.
Lay out units in a 3x3 grid. Place the 4 QST units at the top, left, right, and bottom positions (the 'cross' positions). Place the 4 corner HST units in the corners with the colored triangles oriented inward. Place the background center square in the middle. Rotate each piece so the colored sections overlap visually like fanned cards.
Sew each row of three units together with 1/4 inch seams. Press Row 1 and Row 3 seams toward the corners. Press Row 2 seams toward the center square.
Join the three rows, pinning at every seam intersection to ensure points match. Sew with 1/4 inch seams. Press row-joining seams open to reduce bulk. The finished block should measure 12 1/2 inches square.
Verify that each of the four 'cards' appears to tuck behind the next in a clockwise (or counterclockwise) sequence. If a card does not read correctly, check the orientation of the QST unit in that position.
See how this traditional pattern looks in different color combinations.
Straight set with 2-inch sashing — 4x5 blocks for a 58 x 76 inch throw
Alternating with plain blocks to showcase each Card Trick individually
All four fabrics consistent across blocks for a coordinated woven look