New retainer material for 750 thread count mask

Mid 2021 update:  High thread count cotton and/or multi-layer polyester satin isn't a good choice for high filtration masks. They're not breathable enough at mid filtration performance. And additional layering to get to hight filtration still only decreases breathability further. With that they get hot and uncomfortable as well as giving your chest muscles a good workout.

Context: 

These masks are for places with access to sewing equipment

and hight thread count cotton .. and no access or budget for

N95, FFP2, FK94 etc (with a one-per-day requirement) .

.. say the developing world.

New retainer for the existing750 TPI mask design (rag mask max)

In the local pound store (dollar store) I found a mesh 

that's used to strain chips (UK) french fries (US). 

£1 ... perfect after some scissor work.

It holds a shape perfectly inside the mask. 

I'm not yet sure what it is made of 

- I hope not PVC (off gassing)

Reminder: without the retainer this mask is a decent 

suffocation device. The retainer forces a 3D effect 

and creates a decent surface area to pull air through 

with that collapsing onto your nostrils and lips.

Feb 23rd update

I've put it on and taken it off a few times from shopping trips. 

The retainer is beginning to weaken along the central vertical 

section.  Luckily I have some copper wire left over from some 

retainer experiments a year ago:

This really improves the 3D shape of the mask. Regardless of 

the longevity and suitability of the plastic retainer, this is 

the max breathability I'm ever going to be able to make with 

the RagMask Max design and and 750 TPI cotton fabric