From Marti Michell Quilting Blog: Chart 49: Half-Square Triangles and Eva, Block 31 in the Farmer's Wife 1930s Sew Along

Congratulations to Grainline Geeks

Eva’s grid design provides the perfect opportunity to show off your Grainline IQ regarding half-square triangles. Grainline Geeks always try to look ahead and visualize the best way to cut individual pieces so that, whenever possible, sub-units, blocks and quilt tops all have straight grain on all outside edges. They know thoughtful cutting can eliminate fluttery, rippling edges seen on some blocks.

Grainline Geeks also know that there is more than one way to cut a half-square triangle. Therefore, when they see a HST in a block, they make a conscious decision on the best way to cut each one.

The two most common ways to cut HST are:
• Cutting with the legs on straight grain
• Cutting with the hypotenuse on straight grain

Template Cutting HSTs

In Eva, there are 8 half-square triangles and 4 are cut each way. For those of you using the From Marti Michell templates and our PDF conversion charts, the cutting diagram for Eva shows the perfect way to cut all 8 triangles from one strip of fabric.

Ruler Cutting HSTs

Here are a few grainline geek tips if you are ruler cutting.

Do you need the legs on straight grain?

Naturally, you will add 7/8-inch to the size of the finished HST, cut a square that size and cut it in half diagonally. If you need 4 triangles for a block because you have one in each corner, as with Eva, try to remember to cut the squares in opposite directions, especially if the fabric has any directional design at all.

Then position as shown and all lines will go in the same direction.

Do you need the hypotenuse on the straight grain?

Well, this time you add 1-1/4 inches to the length of the finished hypotenuse and cut a square that size, then cut it in half diagonally in both directions.

If you read last week’s blog, you know I don’t recommend this method for the setting triangles needed for the rows of blocks in Laurie’s quilt layout because some will be crosswise and some lengthwise. However, I don’t mind it so much in a block. In fact, it is a good thing if there is any directional design in the fabric.

Don’t Forget the Corner Trimmer

If you are ruler cutting, I hope you have a From Marti Michell corner trimmer or are using the engineered corners on any of our right triangle templates to nub off the pointed dog-ears on the triangles. It only takes a few seconds, and it makes a world of difference in your finished work.

This is how much fabric is trimmed off every 45° angle corner! Just think how the bulk of untrimmed corners builds up on 6-inch blocks! The real payoff is that our engineered corners make it easy to align the triangles with other patchwork in your block.

Paper Piecing HSTs

Many people who paper piece think that the rigidity of the paper will allow them to ignore grainline guidelines. However, when you pull away the paper there is a great risk of stretching seams and outside edges of the block. As the blocks are joined, they are vulnerable and when the finished quilt is washed, the off-grain pieces love to act out by wrinkling and puckering to show everyone just where they are.

Coming Soon - Peaky and Spike!

Have you met Peaky and Spike? If you connect the center point of one side of a square with both opposite corners, you will get 3 triangles. Two are asymmetrical and are mirror image shapes. One is symmetrical and easily confused with an equilateral triangle, but beware, it is not. Instead, two of the angles on this triangle are 63.25 and the other is 53.5 degrees. That is why people love to cut these triangles with templates or specialty rulers. We have templates for both triangles.

While you will love cutting with the acrylic tools, it is the engineered corners that will make sewing Peaky and Spike a dream.

Why are They called Peaky and Spike?

Sometime in the 1980s, the late Doreen Speckmann affectionately named this pair of triangles, her favorite patchwork shapes, “Peaky and Spike” and introduced them to quilters around the world. In her honor, we continue the tradition of calling them by their famous nicknames and hope you will, too. You will probably be surprised to know the big triangle is Spike and the little guy is Peaky. Her books that explain why are now out of print, but look for them in your guild library or shop for them on eBay®: Pattern Play (C&T Publishing,1993) and Travels with Peaky and Spike (1999). Both books are loaded with designs featuring Peaky and Spike.

Peaky and Spike shapes are in Set D, but those pieces are size-specific to make 4-inch squares. We will write about how to adapt them to the small blocks. However, we now have a multi-size Peaky and Spike set for cutting triangle sets from 1 to 6 inches every half-inch. Product #8289. Ask for it at your favorite quilt shop or visit our website.