Curved Piecing Bias Evaluation

I was cutting fabric to prepare to test out the Meringue quilt pattern, and I noticed that I could get a little bit creative and save some fabric if I cut drunkard’s path concave templates differently than I normally recommend in a pattern. Well, one thing lead to another and I decided it was worth a side trip of effort to evaluate where the bias edges fall when piecing curves and the pros and cons of altering from standard practice. Let’s take a look!

Curved Piecing Bias Evaluation - Standard Concave versus Space Saving Concave Cutting Orientation

Curved Piecing Bias Evaluation – Standard Concave versus Space Saving Concave Cutting Orientation

A standard pattern will be written such that concave templates get cut so that the outside, long straight edges of the template align with the straight grain of the fabric. When cutting concave templates this way, the center of the curve will be a bias edge. And the templates can be rotated along a width of fabric to make the most economical cutting.

I did not have a large enough piece of fabric remaining from my desired fabric to cut my templates in this standard way, but I noticed that I could rotate the template 45-degrees so that the outside, long straight edges of the template are bias cuts. When cutting concave templates this way, the center of the curve will be more aligned with the straight grain of the fabric.

So, I did what any sane quilter would do: I cut what I needed, placed an order for more fabric, and then dug in my fabric bins and decided to test out what it is like to sew quarter circle curves with the concave pieces cut differently. (That is what a sane quilter would do, right? Maybe don’t answer that question, haha!)

Curved Piecing Bias Evaluation - Pieces Cut

Curved Piecing Bias Evaluation – Pieces Cut

To evaluate the difference, I wanted to make sure I was working with the same kind of fabric, so I found scraps of Kona Cotton in Mustard (the lightest fabric / convex shapes), Spice (the concave shape with the edges aligned with the fabric straight grain as typically recommended), and Ochre (the concave shape with the edges aligned with the bias). Note that I am testing this out using 6″ finished templates.

Curved Piecing Bias Evaluation - Pieces Pinned

Curved Piecing Bias Evaluation – Pieces Pinned

When sewing curves, I like to pin my pieces together (pinning tip). When pinning, I mark the center and quarter points along both curves. I start by pinning the center marks together, then the two ends, and finally the two quarter points. The reason I pin this way is that with a typically cut concave piece, the short legs of the concave piece are aligned closely with the straight grain and I find it much easier to get the beginning and end pinned before pinning the quarter points because as the curve starts to transition to the bias, it’s easer to flex the concave shape to match the registration marks.

When I was pinning these two different concave shapes, I didn’t notice a huge difference in the way pinning the curves went together. I was trying to keep in mind that the straight edges of the Ochre concave piece were cut on the bias, but in general I didn’t feel like pinning the curve was manipulating those edges in a way that would stretch and distort the fabric.

Curved Piecing Bias Evaluation - Sewn Seam

Curved Piecing Bias Evaluation – Sewn Seam

I did, however, notice a big difference in how the fabric behaves as I was sewing the curve seam. I started with the Spice concave piece which is cut as I am used to. For whatever reason, I tend to struggle to align the raw edges of the seam at the very end of the curve. I think transitioning from straight into bias at the beginning of the seam works well, but transitioning from the bias back to straight grain just tends to take a bit more patience for me.

As I was sewing the Ochre concave piece, the experience was much different. I noticed as I was sewing toward the center registration point that the raw edges of the fabrics were a bit more difficult to keep aligned smoothly. Again, this is absolutely related to the fact that I was sewing at the straight grain area of the concave curve. Transitioning away from the center down to the end of the curve was very smooth and easy as compared to my normal experience, though.

Curved Piecing Bias Evaluation - Pressed Blocks

Curved Piecing Bias Evaluation – Pressed Blocks

I like to press my curve seams toward the concave piece, and I generally take my time and try not to distort the block when I’m pressing the seam. Other than keeping in mind that the Ochre edges of the concave shape were bias edges, I did not notice a big difference as I pressed. However, when I photographed the blocks, the edges of the Ochre block do not look like they lay as flat; because of the bias, they are a bit more wavy.

Curved Piecing Bias Evaluation - Trimmed Blocks

Curved Piecing Bias Evaluation – Trimmed Blocks

Both blocks squared up nicely.

At this point, I am comfortable moving ahead using the fabric saving concave pieces that I cut from fabric, but I will definitely be handling those pieces carefully until they are sewn into the pattern. What that means is that when possible, I will not let the bias edges be on the presser foot side of the seam and I will reduce my presser foot pressure when sewing the block seams so that I do not distort those edges as I sew.

For beginner sewers and sewers new to sewing curves, I would not recommend cutting concave shapes to have bias edges on the long, straight sides. But if you are in a pinch, rotating your template to make good use of fabric (or to get a cute fussy cut print to show), I think you can still obtain a wonderful result with just a bit more care as you handle those bias edges.

Prefer to have your tutorials in video format? Not a problem, I created a YouTube video of this which also includes a demonstration of how the curves came together while I was sewing them at my sewing machine.

11 thoughts on “Curved Piecing Bias Evaluation

  1. Rosemarie says:

    HelloYvonne. Many thanks for your thoughtful and complete reviews; I always learn something. In this case, I had the same experience cutting large (12″) curves, and like you, will continue to cut with the grain. Take good care, Rosemarie

  2. I love this! Finally, someone who thinks like I do – break the rules to find out why they are rules. So often, those “hard” rules should have an explanation like this. Thank you for such a great exploration and documentation!

  3. Dawn says:

    Thank you for the detail testing of this change in method. Good to know that in a pinch you can rotate the template and with a little care the block still works!

  4. Patty says:

    This is so helpful! I confess to haphazardly cutting my concave when low on fabric in the past and always wondered whether the end result was due to the bias position or my own skill levels.

  5. Debbie says:

    Very interesting indeed! Thanks for going down the rabbit hole for us – good to know!

  6. I would never have tried that because I would presume that the straight grain would not behave at all along the curve! What an illumination to watch you walk us through this and show that it CAN be done, grasshopper. Lol I can see this being especially helpful for fussy cutting.

  7. What an awesome resource on curves and bias. Thanks so much!

  8. cindy-liveacolorfullife says:

    This was so interesting. I have always used the tip by Very Kerry Berry on her blog from quite a few years ago. She sews the conventional way, and then when she gets about 2-ish inches from the end, she stops, turns the piece around and sews from the end back to where the stitching stopped. Does that make sense? It has always worked for me. I think she has a tutorial video on her blog.

  9. A very useful experiment to try before you get to the main project. It’s always good to know the right way to break a convention.

  10. Elizabeth E. says:

    I saw this on IG, and that it was a good thing to have out in the universe. I like where your curiosity leads you!

  11. I found the results of this very interesting. I would have thought that having the curve cut more with the straight grain would have meant the curve would be hard to sew smoothly, so I was surprised to see that it worked so well. Thanks for sharing your experiment, Yvonne!

I really appreciate the time and thought you take to comment, and I look forward to conversing with you. :)