These are all Dropbox files. They’re all open for use, and I only ask attribution if you use any of this. No commercial use, please. Give these away, don’t be a profiteer.
Print the mask images at 100% on US letter or 100%, no scaling. Just cut them out around the edges. Use a straight edge (on the straight lines) if you need it. They will cut straight with a rotary cutter.
Final child & small adult masks are posted. There is no way to make a PM2.5 fit in a smaller mask, and cutting one destroys its structural integrity. Smaller lungs don’t have as much sucking power, so using something like a vacuum bag is likely to make breathing too difficult for small people. Therefore, don’t make a pocketed lining. Just cut and sew the lining exactly like the front. With interfacing or interlining, the mask is 3 layers. And if you have a vulnerable child, stay home as much as possible.
The child and small adult masks are sized for children above about age 5.
The tutorials are long, but detailed. They’re both beginner sewing projects; the flat mask is more beginner than the curved mask.
The flat mask can be shortened on both dimensions for smaller faces. Just try to keep the proportions. The pleats will need to be smaller for a smaller mask.
If you would prefer more pleats or knife pleats, you can use this tutorial.