Last week, inspired to finish up projects laying dormant on my shelves to ready them for their next adventure, I shared my piecing challenges with diamond shapes cut from 2-1/2" strips. Happily, I think I have the floral print piecing mastered with more careful cutting and sewing.
As I left off last time, I had decided to adjust the pattern instructions that called for adding scrappy light-valued 2-1/2" strip segments to each odd angle.
As stated, this technique isn't all that unusual, as patterns go, but I'd just as soon avoid the bias edges that it leaves on the outside of the block if I can and create setting triangles instead.
The 'problem' is the small diamonds, have 45-degree angles at the pointy-points. The angle at the orange star needed for a setting triangle is 22-1/2- degrees.
There are plenty of rulers (or lines on rulers) in the quilting world that will assist with making 45-degree, 30-degree, and 60-degree cuts, as well as a few other angles, but none that I know of to assist in cutting 22-1/2-degree angles. Even tools used to make peaky and spike blocks aren't quite the correct geometry. And even if there were such a tool out there somewhere, I'll probably use this template and technique exactly once for this one project, so finding a short-term creative solution feels more savvy.
After I scratched my head for a bit, the solution was pretty easy, and I only needed a piece of copy paper and some ruler stickers.
Each corner of a piece of paper is 90-degrees. Half of that is 45-degrees, and half of that is 22-1/2-degrees. So if I fold my paper in half diagonally twice so the folds intersect the corner, that's the angle I need.
Then if I lay my ruler on the paper with the ruler edge aligned with one side of the paper as shown, and mark the ruler with a series of stickers to form a line along the other edge of the paper, I'm ready to start cutting.
For the two photos below I've switched to a pale blue solid fabric. The color is so light it almost looks like I'm still using the white paper. I tried a few other prints, but I liked this shade of light blue best to go with the floral diamond shapes cut from the strip set.
First, I cut strips that are long enough to more than accommodate the setting triangle needed--in this case 11" strips--I'll trim the block after the setting triangles are sewn. I keep each strip= folded as it comes off the bolt, so I can cut two layers of mirror-shaped triangles at once. Once I true up the strip edge, I then align the ruler stickers with the fabric edge and cut along the straight edge of the ruler (the diagonal on the fabric) (below left). Then straighten up the ruler to cut along the 'straight-of-grain' of both ruler and fabric as shown (below right).
Pretty quickly, I've got a stack of setting triangles to add to the diamond block center.
I'm averaging a couple of blocks during my daily hour-long morning sewing sessions. That includes some of the backwards sewing to repair the blocks for better accuracy. About 10 blocks done. 50 or so more to go!
I don't know that this particular issue would be a common problem in the sewing studio. Most diamond shaped blocks tend to start with some variation of a 30-degree cut--and there are lots of 30/60-degree tools on the market. I'm glad to say that everything I needed to solve this challenge was already in my bag of tricks!
I think the project designer found an interesting way to use a 45-degree strip template that might normally be used for a pattern, like the lone star, that depends on 45-degree angles throughout the design.