Patchwork Block Diagram 🧩

How to Use the Block Diagram Tool

Pick a patchwork pattern, enter your finished block size, and set the seam allowance (1/4" is the quilting standard). The tool draws every piece in the block and automatically applies seam allowance to each edge.

Toggle "exploded view" to see each piece with its seam allowance rendered as a dashed outline around the finished shape. This mirrors a quilt pattern technical drawing: solid = visible finished edge, dashed = seam to sew.

The cutting list groups identical pieces so you can cut in one pass. HST (half-square triangle) squares include the traditional +3/8" bias trim buffer so the sewn-and-squared triangle finishes exactly to size.