in italy due to the epidemic coronavirus covid19 the protective masks have become hard to find, as well as excessively expensive, so I would have developed a fairly effective type easily achievable by yourself.

Note: this homemade protection has been carefully designed, but does not want to replace professional and certified products, it represents emergency protection when you can't get better!

Supplies

the list of necessary materials:
cotton fabric (... sheets)

filter paper (from eBay: you can choose from 0.15 to 0.01)

soft plastic sheet

sewing thread

tetra pack caps or similar

elastic tape

cardboard for cutting patterns

work tools:

cutting plan (even simple cardboard)

scissors or cutter

5mm hole punch

needle and thread or sewing machine (..best choice)

Step 1:

this mask model is obtained from only two twin parts joined by a scar; first of all you have to detect the cutting patterns on cardboard, the optimal shape is easily obtainable from a template obtained by modeling, with folds and the help of adhesive tape, a light paper lying on the face. Then this shape will be shown on the cardboard which will be the definitive model for cutting the fabric, in fact.
The models for cutting the filters and the plastic sheet that will prevent the entry of air out of the filter area will also be obtained from this...however there is a 1:1 scale image in unit.

By means of these models we can now cut the material necessary for the practical realization !

Step 2:

We begin by placing the paper filter, then the soft plastic insert in which we will have cut the hole in correspondence with the underlying filter, after which we close everything in sandwich.

Remember that the sandwiches needed to make a mask are two, one right and one left, so take care in the position of the filter, that would be under the plastic sheet!

Now overlap the two sandwiches, matching the edges and joining by sewing the curved part as shown.
Elastic laces are also attached by stitching

Step 3:

Now just turn the mask over and bring the seam inside, and it is ready to be worn.

If additional protection is desired, external filters can be added, using the simple caps already mentioned.
They are drilled as shown in the picture with the punching die, OILED cotton

for maximum capturing or additional filter paper discs are inserted, they are glued to the outside edge in correspondence with the holes in the internal plastic sheet.

this mask could be reused when sanitized in alcohol or, probably, by UV rays, no component will suffer from the treatment, less the oiled cotton which will have to be replaced...

if you do enough, they will be like the winchester, that loads on Sunday and shoots all week ;)

! thanks for looking !