As I began to piece the columns together, I noticed the setting triangles were rippled. Of course, this is because they began as squares that were cut diagonally leaving the biased edge exposed on the outside column edge. Bias edges are stretchy, hence rippled edges. Just by sewing and handling the fabric, stretch occurs. In a perfect world, the outer edges of setting triangles should be on the straight of grain which these could be if they were quarter-square triangles. As the designer, I decided against quarter-squares triangles due to fabric requirements: 13 1/4" squares for half-square triangles or an 18" square for quarter-square triangles. A measurable difference when considering that only one or two triangles are required for this project. So how do I protect the edges from stretching any further? By basting the edges around the entire column. The basting will stabilize the raw edges.
I set my machine straight stitch to 4.5.
I want to baste about 1/8" outside of my black point. At 1/8", the basting will be hidden by the 1/4" seam allowance (hopefully). However, as I didn't want to mark the 1/8", I found a place on the outside of my presser foot that would accomplish same.
The basting is complete and I now need to trim the column to create a 1/4" inch seam allowance.
The 1/4" ruler mark is placed on the black point of the side of the on-point square and lined up with the next black point and then trimmed, continuing to trim until the whole column is done.
With the basting and trimming complete, the columns can now be joined together.
While the majority of the basting stitches will be hidden beneath the seam, if any are showing (like these) I will rip them out, very easy to do with such a large stitch.
If using bias edges, consider stabilizing the bias BEFORE you cut and create them with starch or pre-basting on either side of the cutting line through the center of the square.