Notions Guide
Specialty Quilting Rulers Guide
What Easy Angle, Companion Angle, and other specialty triangle rulers actually do — and when a plain ruler and the formula is enough.
Easy Angle
Half-square triangles (45°)
How it works: Cut straight strips at the finished size + 7/8", then use the ruler to slice triangles directly from the strip — no drawn diagonal line, no squaring up after sewing.
What it saves: Cuts straight from the finished size (no separate add-7/8" math needed on a square first), and gets more triangles per strip than cutting oversized squares individually.
Shop this ruler on AmazonCompanion Angle
Quarter-square triangles (90°) — the side-setting-triangle shape
How it works: The quarter-square counterpart to Easy Angle — used for setting triangles and any block needing a triangle with the straight grain on its long edge.
What it saves: Same strip-cutting efficiency as Easy Angle, sized for the quarter-square (side-setting-triangle) cut instead of the half-square cut.
Shop this ruler on AmazonCreative Grids 45° / 90° Triangle Rulers
Half-square and quarter-square triangles
How it works: A comparable alternative to Easy Angle / Companion Angle from a different brand, with a frosted non-slip edge along one side for grip.
What it saves: Functionally the same cuts as the pair above — brand preference and edge-grip feel are the main differences.
Shop this ruler on AmazonSquare-Up Ruler (various sizes)
Trims any pieced unit to an exact final size
How it works: Used after piecing, not before cutting — lines up the sewn seams and trims the block to a precise square or rectangle, removing the built-in oversizing from the stitch-and-trim method.
What it saves: Not a cutting-math shortcut like the others — this is what turns an intentionally oversized pieced unit (HST, HRT, flying geese) into an exact finished size.
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Cutting the same shape hundreds of times?
Past a certain volume, even the best specialty ruler becomes the slow way. Die-cutting systems like AccuQuilt's GO! cutters stamp out perfectly consistent HSTs, tumblers, and appliqué shapes by the stack — a real consideration for scrap quilters, guild charity sewing, and anyone whose rotary-cutting wrist has opinions at the end of a cutting day.
Browse AccuQuilt cutters & diesFrequently Asked Questions
What is the Easy Angle ruler for?+
Cutting half-square triangles directly from a fabric strip at the finished size, without drawing a diagonal line or doing the add-7/8" square math yourself. It's designed to work from strips cut to (finished HST size + 7/8") wide.
What's the difference between Easy Angle and Companion Angle?+
Easy Angle cuts half-square triangles (a 45° triangle, two per square). Companion Angle cuts quarter-square triangles (a 90° triangle, four per square) — the shape used for side setting triangles and any block needing the straight grain on the triangle's long outer edge.
Do I need specialty rulers, or can I use the calculator formulas instead?+
Either works — the cut-size formulas on this site's calculators (HST, HRT, setting triangles, flying geese) get you the same finished units using just a rotary ruler with a ruled grid. Specialty rulers trade a bit of cost for speed and less fabric waste when you're making the same unit repeatedly in volume.
What is a square-up ruler used for?+
Trimming a pieced unit down to its exact finished size after sewing — most relevant for units deliberately cut oversized and trimmed afterward, like half-rectangle triangles or the stitch-and-flip corner method. It's a finishing tool, not a cutting-before-sewing tool.