I imagine that most everyone reading this post has a sense of the various styles of face mask sewing patterns out there, each pattern with its own pros and cons. This center seam version is the style I’m focusing on at the moment. I like that there are minimal gaps around the mask. The curved top edge fits well around the nose without a wire, especially when you add fusible interfacing to the cotton quilting fabric to give it extra body. And the ties allow for a more flexible fit than elastic bands.
But I did make a change to the typical instructions for this style of mask that I wanted to pass along in case other people found it useful: For the seam that runs down the middle of the mask, I press the seam allowance to one side and then topstitch the seam allowance to the mask. Typically, the instructions for this style mask call for pressing this seam allowance open.
Now, I don’t know if my approach to finishing the seam makes a real difference in how the mask works, and we know that fabric masks don’t provide as much protection as medical grade masks, but my thought is that pressing the seam allowance to one side and securing it to the mask with top stitching provides more closure for the seam than pressing the seam open.
For those not familiar with the term topstitching, I mean that after I sew the middle seam, I press the seam allowance to one side of the seam. Then I turn the fabric over, and with the right side of the fabric facing up I sew close to the seam, in this case about 1/8” (3mm) away from the seam, in the process sewing the seam allowance to the body of the face mask.
I finish both cloth layers for the mask the same way. For both layers I press the center seam allowance to the same side of the seam, in this case to the right of the seam allowance when looking at the wrong side of the fabric. By pressing the seam allowances to the same side for both layers, the seam allowances lie on opposite sides of the seam when the layers are sewn together.
Here are some additional tips
1. As I mentioned earlier, adding fusible interfacing to the wrong side of one layer of fabric adds body and helps the mask hold its shape around the curves. I cut the interfacing from the same pattern piece as the face mask, and I don’t trim it before fusing it to the fabric.
2. Wash the fabrics to pre-shrink them before cutting them, and pre-shrink your interfacing as well if the manufacturer’s instructions call for it.
3. Before pressing the seam allowances to one side, I trim them with pinking shears. Pinking gives a similar affect to clipping the seam allowance along the curves, but it’s faster. Just be sure to leave at least 1/8” of the seam allowance intact for the top stitching. (Pinking shears Amazon affiliate link).
4. Before top stitching the center seam allowance, be sure to press the seam along the curve. A tailor’s ham can be useful for pressing curved seams if you have one. I don’t have a tailors’ ham, so I use a piece of heavy wool that I roll up into a ball and I lay the curved seam over that.