Grandmother's Cross Quilt Block

The Grandmother's Cross quilt block belongs to a family of blocks whose inner units are on-point. (One of the simplest blocks from this family is the Square in a Square. Another similarly constructed block is Mosaic #3.)

In this tutorial, you'll find both a some-cost and a no-cost alternative to make it using either a specialty ruler or templates.

Choose the method that most appeals to you.

Grandma's not cross, but she'd sure like you to get started with her block!

The On-Point is the perfect tool for cutting squares, rectangles or half square triangles that are 'on-point' in a block. The orange and yellow squares in our Grandmother's Cross are just such units.

If you look closely at our cut strip when it's measured with a regular rotary ruler, the strip width is just shy of 2" wide.

Now that might not look like much, but if I'm going to go to the bother of perfecting my quarter inch seam allowance, it seems silly to me to then be willing to 'fudge' the measurement of these strips.

That's why I don't rotary cut these units with my standard rulers.

With right sides together (RST), stitch #3 and #4 strips together along the long edge with a 1/4" seam allowance.

Press unopened to set the seam and then open with the SA towards the darker fabric.

Again using the OPRuler, subcut the strip-set into units using the chart below.

Finished Block Size	Width of StripSet after stitching	Subcut Width
4"	2”	1”
6"	3”	1 1/2”
8"	4”	2”
10"	5”	2 1/2”

Align the subcut measurement (in this case 2" for this 8" finished sample block) with the straightened edge of the strip set (white arrow). Cut along the clear opposite edge (black arrow).

Cut 10.

From this point forward, the instructions are the same for either cutting method.

With RST, stitch the pairs together.

In the center, pick out a few stitches to release the SA and twirl the seams as shown below. Press.

Starting with the upper right four-patch, with RST align a shorter edge of a #2 triangle with the edge of the four-patch. Since the tail on the triangle is so long, I prefer to pin to hold things in place.

Stitch, starting from the even side.

Stitch the second #2 to the opposite side of the four-patch.

Press with SA toward the #2s.

If you stitched with an accurate 1/4" SA, the triangle will extend a smidge past the bottom of the 4-patch. (white arrows below)

To find the center of the #1 triangle, fold it in half and fingerpress a crease. You can just make it out above.

With RST, match this crease with the seam in the 4-patch. Pin.

This time, your 1/4" seam should begin and end in the valley created by the patches. (white arrow below).

Use a stiletto (the point of your seam ripper or a bamboo skewer will do in a pinch) to hold the long points of the #1 in place during sewing.

Press with the SA toward #1.  Create another unit like this starting with the lower right 4-patch.

To make the center row, with RST stitch the three 4-patches together paying careful attention to the direction of the SAs. Stitch a #1 to each short end, folding and fingerpressing the #1's in half to find their centers.

With RST, add the #1s to each end of this center unit in the same way as the corners.

With RST, match and pin a corner to one side of the center. Again, your 1/4" SA starts and ends in the valley created by the two units.

Add the second corner unit to the opposite side.

Press with the SA away from the center.

This is the finished Grandmother's Cross quilt block.