0. materials:
- woven pure cotton material, preferably a fine lawn (handkerchiefs OK),
- cotton thread such as that used for kippot,
- 5-10 pins
- sewing thread,
- thin needle,
- larger eyed needle
- crochet hook, scissors.
- pdf of pattern  (download from   http://phony1.technion.ac.il/~phr76ja/craft/scanmask.pdf) 
1. print the pattern, and cut along the dashed line.
2. prepare two  pieces of material (can be the same or different patterns).
3. fold each piece of material in the middle.
4. for each place the edge labelled fold on the fold and cut two
mask shapes along the dashed lines - 
5. sew the 4 darts (indicated by the solid lines), two on each piece,
so they face to the wrong side of the material, and iron flat.
6. place the material right sides facing.
7. sew together around the outside,  (could use a sewing machine,
but also OK  by hand) 1/3 cm from the edge  leaving a 1cm gap
to turn inside out. turn, then stitch the gap closed.
8. thread the large eyed needle with the kipa thread, and do
blanket stich along one side edge  (A to B). crochet  a row of chain between
B and A and adjust  so  it comfortably goes around  your ear.
9. place a single crochet or two in each top of the blanket stitch,
continue along the row of chain
stitch and then crochet another one or two rows. Fasten the end and
repeat  along the other side.

10. handwash and iron (iron helps sterilise); I wash and iron after every
few wears.