Seam and Seal

00The bench

Bench log, numbered sheets

Masks and respirators, one numbered sheet at a time

Plain-language task sheets on how masks work, how to fit, wear, wash and make them, and what the standards and the evidence say. Every rule carries the date of the page it came from.

12345 outer layerfilter layerinner layer ear loopnose wire
Plate 00. A layered mask in exploded view: 1 outer layer, 2 filter layer, 3 inner layer, 4 ear loop, 5 nose wire. Sheet 01 explains what each layer does.

Task register

  1. 01How masks and respirators workFiltration, the leak path, and why droplets and aerosols are treated differently.Explain5 min
  2. 02Types of masks and respiratorsCloth, medical, FFP2, N95, KN95 and elastomeric: what each name means.Explain4 min
  3. 03The standards behind masksWhat EN 149, EN 14683 and NIOSH approval test, and what they leave out.Explain4 min
  4. 04Fit and seal checkWhy a seal matters, what changes the fit, and how a user seal check works.Task5 min
  5. 05Putting on and taking offThe order of steps for fitting and removing a mask, with the reasons.Task4 min
  6. 06Counterfeit respiratorsHow to check a respirator against the issuing body's own markings and listings.Check4 min
  7. 07Caring for reusable masksWashing, drying and retiring reusable masks, as public guidance describes.Task4 min
  8. 08How to make a cloth maskA dated, sourced method for a cloth mask, with its honest limits.Task4 min
  9. 09What the evidence saysWhat trials and reviews show, and why mask studies are hard to run.Explain4 min
  10. 10Masks and childrenWhat public health bodies said about children, with the age lines and dates.Explain4 min
  11. 11Glasses and hearing aidsFogged lenses and ear-loop strain: what helps, with sources.Task4 min
  12. 12Headaches and skin irritationWhat studies report, and when a symptom needs a clinician.Explain4 min
  13. 13Who should still wear oneA cautious, dated look at who is advised to wear one, where and when.Check3 min
  14. 14A short historyDated entries on how mask wearing developed, each tied to a source.Explain4 min

How to read a sheet

1

The number

Sheets are numbered 01 to 14. Clauses inside are numbered too (04.2 is the second clause of sheet 04), so a correction can point to one paragraph.

2

The plate

Each sheet carries a line drawing made for the page. Plates show how a thing works. Where one is a schematic and not data, its caption says so.

3

The date

Rules are written "as at" the date of the page they came from. The sources and dates page lists them all and explains the method.

An independent publication. It sells nothing, ships nothing and gives no personal advice. The about page says more.