The pouch design is identical to the paper version, but has three layers - an inner layer, an outer layer, and in between an impermeable membrane. It is formed into two pouches, one to hold the filter, and another on top to encompass the nose and press into the cheekbones to better seal the top and prevent glasses fog.

If you dont wear glasses, you wont miss the fog, believe me. Commercial masks are a regular pain by all accounts, I know how bad dust masks are for fogging.

How To Make

First of all you'll need three layers. These measure 6" tall and 10" wide. Two are cloth, I've used black polyester for the outside and white cotton for the inside, the plastic membrane is cut from a shopping bag - a decent one, not those disposable ones that break down over time.

Stack them in order, inside on top, outside underneath, and the membrane on the bottom. This is necessary to make a hem with the membrane in between the cloth.

After hemming the layers together, take the top layer and fold it underneath to turn the mask in the right way.

Next fold the top third down, then fold it in half back up again. Then do the same for the bottom third.

Seal down the pleats by sewing straight down the edges. You might need to pin them in place first but you dont need to be neat about this.

Next sew in from each edge catching the bottom edge of the top pleat both ends. You'll need to go in two to three inches depending how big your nose is... The seams here pull the pleat in and down to meet the skin either side of the nose and seal it better.

You can do without this step if you dont wear glasses but a decent seal all around is safer, all the air has to travel through cloth to get inside.

Finally insert a makeup pad between the inner layer and the plastic membrane to complete the filter.

Obviously it needs a strap or rubber bands the same as any mask, but this design is extremely comfortable and can be hand-washed in warm water when it starts to get funky.

Paper masks dont get the chance, but wear the same mask over and over and they get damp and can go mouldy. A bandana has the same problem, you must wash these regularly or you can infect yourself with mould spores.

Aspergillosis is common, and isnt funny.