Setting Blocks on Point

After seeing my Spiky 16 Patch quilt, Mrs. K asked that i give the math on putting blocks on point. This post is an addition or adjunct to the Sampler Class tutorials. Different quilt, but you can use this information to put your sampler blocks on point as well.

There are two aspects to putting blocks on point: the setting triangles and the corner triangles. The setting triangles are on the inside of the quilt. The corner triangles are on, shockingly, on the corners.

In the photo, right, the corner triangles are indicated by the orange half circle. The setting triangles are shown with a purple circle.

Setting Triangles

Setting Triangles, also called side triangles, are giant quarter square triangles. You want to use this method, because the bias will end up on the outside of the block.

1. Measure the block.

In the quilt above you want it to end up looking like it is shown. The Spiky 16 patches.

The Spiky 16 patch measures 16.5 inches.

2. Take the finished block size and divide by 1.414.

Note: the finished block size is different than what we measured. You need to remove .5 inches for seam allowance, which gives you a finished block size of 16 inches.

16 x 1.414 = 22.624

3.  Round up

I rounded up to 22.75, but you can round up to an eighth of an inch, if you want.

4. Add 1-1/4″ to the resulting number for the correct size to cut squares for side triangles.

22.75 + 1.25 = 24

5. Cut this square in half diagonally twice in the shape of an X to produce four side triangles.

Nota bene: Cut one square for every four side triangles needed for the quilt setting.

6. Lay setting triangles next to your blocks to make the quilt square.

YAY! You did it!

Corner Triangles

1. Measure the block.

In the quilt above you want it to end up looking like it is shown. The Spiky 16 patches.

The Spiky 16 patch measures 16.5 inches.

2. Take the finished block size and divide by 1.414.

Note: the finished block size is different than what we measured. You need to remove .5 inches for seam allowance, which gives you a finished block size of 16 inches.

16 / 1.414 = 11.315417256

3. Round the size up

Take the number you got and round it to the nearest quarter or eighth of an inch. I rounded up to 11.5.

4. Add 7/8 inch

11.5 + 7/8 = 12 3/8

5. Cut two squares the size determined above.

6. Cut both squares in half diagonally.

Now you have four triangles.

7. Place on each corner.

YAY! You did it! You cut corner square triangles. Sew them on. You may need a quick trim and you are done with corners.

Lay all of the setting triangles and corner triangles out with the blocks on your design wall. When you are ready to sew, sew. I fold the blocks and the setting and corner triangles in half so I can line them up properly.

Trim once the whole piece is complete, if necessary.

If you don’t believe me, you can find Bonnie Hunter’s tutorial on Quiltville.

Author: JayeL

Quiltmaker who enjoys writing and frozen chocolate covered bananas.

4 thoughts on “Setting Blocks on Point”

1. Sally Howard says:

Yay – thanks for posting this information. Having straight of grain on the outside edges of a quilt helps so much towards keeping it square. As a longarm quilter I try to tactfully explain this when quilt borders don’t come out perfectly flat. Part two is measuring and pinning borders, and not adding extra inches.

1. Sally- I can’t believe I didn’t think of it before! I hope to revise it with some photos, though I am glad it is clear without them. I think straight of grain on the border is critical, but not everyone agrees or cares. I’ll do a borders post at some point. I usually chunk my borders rather than slapping on long strips, so I’ll have to find a project where the design works with those type of borders.

2. Susan McRae says:

Thank you!!! this is very clear. Also I looked at the Bonnie Hunter link, and printed out her chart with math already done!!! I’ll send pictures when I finish.

1. I am glad this worked for you. I’ll try to add some photos and update the post later. Yes, Bonnie’s is a good page. Sorry I didn’t have a chart available.