Why Squaring Up Matters: Trimming Blocks with the Lori Holt Trim It Ruler
Almost every quilt block comes out of the sewing machine a little imperfect. Seams stretch on the bias, embroidery can pull fabric slightly out of shape, and hand applique rarely lands exactly square. That's where a trimming ruler earns its keep. The Trim It Ruler Square 12-1/2in x 12-1/2in by Lori Holt of Bee in my Bonnet is a non-slip, easy-to-use plastic quilting ruler made specifically for trimming up blocks after piecing, applique, or embroidery. At 12.5" x 12.5", it handles the most common block size in quilting — a 12" finished block (12-1/2" unfinished) — in a single pass.
What Makes This Ruler Different
Quilting rulers all look similar until you use one, and the Trim It line stands out in two ways. First, the markings: aqua and denim lines printed in 1" grids, marked in 1/8" and 1/4" increments on a clear plastic base. The high-contrast colors make the grid easy to read against busy fabrics, light solids, and dark prints alike. Second, the non-slip surface — the ruler stays put while you run your rotary cutter along its edge, so you're far less likely to shave a sliver too much off one side mid-trim.
Centering Your Block with the Diagonal Lines
The ruler's diagonal lines are its most useful feature for trimming. Lay the Trim It ruler over your finished-but-untidy block and line the diagonal up with the block's center or the intersections of its seams. Because the diagonal runs from corner to corner, it lets you center the block under the ruler before you cut — critical when the block has a design you want to keep balanced, like a star point or an embroidered motif. If a block came out slightly skewed, centering on the diagonal shows you exactly how much fabric you have to give on each side, so you trim evenly instead of lopping off one corner.
The 1/4" Seam Allowance Marks: See the Finished Block
Along the outside edge, the ruler prints colored 1/4" seam allowance marks. This is a genuinely clever detail: when the ruler is positioned on your block, the outer marks show you what will disappear into the seam allowance and what will actually show in the finished quilt. It's like previewing the block after it's sewn in. Use these marks to double-check that points won't be cut off, that text stays readable, and that a border or frame around your design is wide enough to survive the seam. Adjust the ruler until the colored lines confirm your design sits safely inside the finished area — then trim.
A Reliable Trimming Routine
Set up for accuracy: a self-healing cutting mat on a flat, stable table, a sharp rotary cutter, and good light. Place your block face up on the mat. Lay the Trim It ruler over it, align the diagonal to center the block, and check the 1/4" allowance marks. Trim the right and top edges first, then rotate the block (or the mat) 180 degrees and trim the remaining two sides. Rotating rather than repositioning the ruler means the already-trimmed edges register against the ruler's grid lines, keeping every side square. For embroidered or appliqued blocks, go slowly — slight tension differences in the fabric can make the ruler shift, so the non-slip backing does real work here.
Care and Longevity
The ruler is clear plastic, so keep it out of direct heat — never leave it on a warm ironing board, and store it flat or hanging rather than wedged where it could warp. Wipe fingerprints off with a soft, dry cloth; avoid solvents that can cloud the markings. Treat the printed aqua and denim lines gently and they'll stay legible for years of block-trimming.
Shop the Trim It Ruler Square 12-1/2in x 12-1/2in at Linda's Electric Quilters.
