Here are links to pdf documents with instructions for creating the Long Flap Mask. There are three different versions: the Fitted Mask, the Pleated Mask, and the No-Sew Mask (using a pre-existing mask). Although it does not offer as much protection, our original flap mask design and instructions are included below in case that is still of use to some people.
Long Flap Mask - Fitted Version
This mask uses a "fitted mask" as the base. It requires the most sewing skill to make.
https://drive.google.com/file/d/1mufpLZABP0uVhhGwAGpXFB7E4dFaCXTp/view?usp=sharing
Long Flap Mask - Pleated Version
This mask uses a "pleated mask" as the base. It requires less sewing skill than the "fitted mask".
https://drive.google.com/file/d/1HD_DHkqJMV5HNtP56zHtzvq12oAv618z/view?usp=sharing
Long Flap Mask - No Sew Version (using an existing mask)
This version can be created without sewing at all. It involves attaching the long flap to an existing mask. Alternately, you could use the sewing instructions for the flap from the fitted or pleated versions and attach a flap to an existing mask.
https://drive.google.com/file/d/1qBU6ZQkiEsUOOXxPTpWa5o66wjuJlSpg/view?usp=sharing
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The Original Flap Mask
This is the first version of the mask with a flap. It has a large mouth opening, so it does not provide as much protection as the Long Flap Mask. It could be of use for outdoor playing or may be preferred by some people for one reason or another, so I am including it here in case anyone is interested.
Printed sewing instructions:
https://drive.google.com/file/d/1_yF3_W0uLNh_4RhXksnVgvRcu4KYDGeB/view?usp=sharing
Sewing Video:
https://www.youtube.com/watch?v=_cfZCY9v-Mw&t=50s