Creative Grids 90-Degree 6-1/2" Quarter-Square Triangle Ruler (CGRT90)

Trying to piece quarter-square triangles (QSTs) usually means struggling with "dog ears" and trying to measure seam allowances on biased edges where the fabric stretches. The Creative Grids CGRT90 is built specifically to stop that stretch. At 6-1/2 inches, this is the precision template for truing up your quarter-square units, ensuring the finished block lies perfectly flat without the distortion common to manual measuring.

This ruler isn't just a guide; it’s a locking mechanism. The patented Creative Grids non-slip grip dots are embedded across the back surface, meaning that as soon as you put your hand on the acrylic, the ruler bites into the fabric. You won't have to deal with the ruler "skating" across your rotary mat mid-cut. Plus, it features clearly marked 1/4-inch seam allowance lines, so you can cut your QSTs and jump straight to the sewing machine without doing extra math.

Why It’s Better

• Stretch-Free Geometry: Designed to align with the grain of the fabric, preventing the warping that ruins bias-heavy quarter-square units.

• Instant Seam Allowance: No more "adding a quarter inch"—the seam lines are pre-printed on the ruler face, turning your cut into a ready-to-sew unit immediately.

• High-Contrast Visibility: The sharp black-and-white grid pops against any fabric color, so you aren't squinting to find your alignment points.

Essential Data

• SKU: CGRT90

• Material: Professional-Grade Clear Acrylic

• Angle: 90-Degree Fixed

• Height: 6-1/2 Inches

Frequently Asked Questions

Is this just for half-square triangles? No, it is designed specifically for quarter-square triangles. It has the correct 90-degree angle to ensure that the tip of your triangle is the correct size once sewn into the block.

Does it actually stick to the fabric? Yes. The grip technology provides a "brake" effect. It slides easily when you need to adjust your alignment, but holds firm the instant you apply downward pressure to cut.

How does this help with bias stretch? Because this ruler gives you a rigid edge to guide your rotary cutter, you are cutting against the ruler's edge rather than trying to measure along a soft, stretchy bias edge. It keeps the fabric stable throughout the entire cut.