While this has been suggested by CDC as better protection, we know that good quality fabric is still protective when made with only 2 layers.
That being said, I'm posting a tutorial for making masks with 3 layers, showing how to eliminate the "bulky" fabric in the side seams (when implementing the folds into them).
Cut fabric 8" wide, by 21" long. Fold into thirds so its 7"x8". Open the bottom third and leaving 1" or so at each end of that third... cut out arcs (this removes the bulk of the sides, while leaving the edges that will hold the elastic edges.)
Fold the "arced" third up to cover the middle third (wrong sides together).
This shows the acrs cut out (I used a rotary cutter).
Fold 1/4"-1/2" of the edge on the opposite end of the arc.
Lay your 7.5" elastic strips on the middle third. The right side is folded with the arced third underneath.
All three layers... fold top third over middle third and pin elastics into corners.
This in the mask, pinned elastics within the folds.
Sew along sides that will catch elastics , going back and forth over elastics, to reinforce the stitching.
Turn inside out (arced sides will end up being the middle layer.
Bottom end is open. I pin this closed, before making my 3 folds and pinning them in place.
Folds pinned, ready to sew all around.
Stitching along folded edges only without the bulky middle layer.
Finished 3-layer cloth mask!
