3×3 Quilt Top Repeater
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Snowball Unit
Square block with four stitch-and-flip triangles on all corners
Recolor Fabric Slots
Block Anatomy & Specs
History & Origins of the Snowball Unit Block
A Snowball Unit is formed by sewing four small squares onto the corners of a larger square and trimming the excess. When combined with Nine Patch or Four Patch blocks, Snowball units create rounded lattice windows.
Cutting & Piecing Guide (12" Finished Block)
Precise unit cut sizes and step-by-step piecing instructions.
Choose a finished block size
The cut measurements below update to match.
Piece Cut List
All measurements include a standard ¼" seam allowance. Finished block size: 12".
Step-by-Step Visual Assembly
Mark a diagonal line on the back of all four corner squares.
Align one corner square on each corner of the main center square, right sides together.
Sew directly on the marked line on all four corners.
Trim 1/4" outside the seam line and press corners open.
Classic Quilt Blocks Built With Snowball Unit
The Snowball Unit unit is the core building block used in these traditional patterns: