How to Use the Creative Grids Square on Square 8" Trim Tool

Published July 2026

Learn how to use the Creative Grids Square on Square 8" Trim Tool with Tammy at Shabby Fabrics! This innovative tool helps you create precise Square-on-Square blocks and even Snail's Trail blocks with ease, ensuring perfect points. Tammy demonstrates how this versatile tool simplifies complex piecing, making it ideal for various quilt projects.

In this video, you'll learn:

• How to accurately cut and sew Square-on-Square blocks using the Creative Grids 8" Trim Tool.
• Tips for pressing seams and trimming blocks to achieve perfect unfinished sizes.
• How to create a stunning Snail's Trail block with precision.

Introduction

Square-in-a-square blocks have a reputation for being fussy. The usual sew-and-flip method eats a lot of fabric, and the blocks rarely come out straight the first time – you end up re-squaring, guessing, and adding more squares on top of a block that's already drifted out of true.

This Creative Grids tool, designed by Jean Ann Wright, takes that problem away. It builds one block in three finished sizes (4", 6", and 8"), and every cutting instruction you need is printed right on the tool. No hunting for the pattern, no downloading anything.

This tutorial covers three blocks made with the same tool: a classic pieced square-in-a-square, a simplified version with a solid center, and a snail's trail.

What You'll Need

• Creative Grids Square on Square 8" Trim Tool (by Jean Ann Wright)
• Rotary cutter with a sharp blade
• Rotating cutting mat (Tammy is using the Creative Grids rotating mat)
• Fine patchwork pins 
• Small sharp scissors for clipping corners (Tammy keeps a pair of Karen Kay Buckley scissors next to her machine)
• Iron and pressing surface
• Fabric – two contrasting fabrics for the blocks shown here

Cutting Chart

All triangles are made by cutting a square in half once on the diagonal, which yields two triangles. Two squares gives you the four triangles needed for one round.

Block 1: The Classic Square in a Square

Step 1 – Start with the center

Place one 2½" square right side up in front of you. That's your center.

Step 2 – Add the first pair of A1 triangles

Cut two 3" squares in half on the diagonal to make four A1 triangles.

Lay one triangle on one side of the center square, right sides together, and one on the opposite side. Sew both seams with a 1/4" seam allowance.

Step 3 – Clip the corners

You'll notice little triangle tips sticking out past the edges on either side, making it harder to see your 1/4" seam allowance at the machine. Snip all four of them off with your scissors, right at the corner to get them out of the way!

Step 4 – Add the second pair of A1 triangles

Flip the unit over and center a triangle on each remaining side, lining up against the little points on either edge. Pin each one in place so it can't shift.

Pin away from the seam allowance – a good healthy 1/4"-plus back from where you'll be sewing – so you can sew straight down without stopping to remove pins.

You're eyeballing the centering here. You can measure it if you want to be exact, but roughly 1/4" of triangle sticking out past each end is what you're aiming for.

Step 5 – Sew

Start your 1/4" seam right in the V where the two fabrics meet – that V is exactly where the quarter inch falls. Sew all the way down to the other end. Repeat on the other side.

Step 6 – Press

Remove the pins, flip the triangles open, and press toward the triangles on both sides.

Step 7 – Trim using guide A1

Now go to the tool. Find the A1 white square printed near the center.

Lay the tool over your block so that white square sits perfectly over your 2½" center square. When it lines up exactly, you know you're positioned correctly. Trim the two exposed sides.

Rotate your block (this is where a rotating mat earns its keep), reposition the tool so the A1 square sits squarely over your center again, and trim the remaining two sides.

Step 8 – Add the A2 round

Cut two 3½" squares in half on the diagonal for four A2 triangles. Add them the same way as before: two opposite sides first, clip the corners, then the remaining two sides. Press out toward the triangles.

Step 9 – Trim using guide A2

This time use the A2 black line on the tool – this marks the new center of your block. Don't reach for A1 again; it'll cut off far too much.

Line the black line up with the center portion of your block. Your A2 triangles should be sitting in the space the outline creates. Trim two sides, rotate, realign, trim the other two.

Measure it: a perfect 4½" square (4" finished). If your pattern calls for a 4½" square-in-a-square, you're done right here.

Step 10 – Add B1 for a 6½" block

Cut two 4½" squares in half on the diagonal. Add them, clip, press.

Trim using the B1 white square on the tool. Center it over the block, trim two sides, rotate, trim the other two.

Result: a perfect 6½" square (6" finished).

Step 11 – Add B2 for an 8½" block

Cut two 5½" squares in half on the diagonal. Add them, clip, press.

Trim using the large black B2 square in the center of the tool. Trim all four sides.

Result: a perfect 8½" square (8" finished)!

Why so much trimming? It looks like a lot of waste, but it's less than sew-and-flip, where half of every square you add ends up in the scrap pile – eight times over. More importantly, oversizing and trimming down guarantees the block is the correct size and the points are right where they should be. The tool cuts exactly 1/4" outside your points every time, so nothing gets chopped off when the block goes into a quilt.