The masks I made using this kit were double sided cotton with interfacing between the two layers, i used a pleated pattern, i have put instructions up on my blog of the masks i made, as i found it more comfortable style, this is only suggestion.
This fabric is not of a medical grade and contains no filters.
This pack contains enough fabric to make 10 face masks, the mask would be double sided with tightly woven cotton fabric, interfaced and elastic to fit around the ears.
The intefacing I have chosen is soft and durable, as this product will be washed on a regular basis, this interfacing has a high level of resistance againt repeated care treatments. The interfacing has good adhesion, iron on to the fabric with a medium iron for approximately 6-8 seconds then let it cool before sewing the rest of the mask together.