We created this guide for drawing and cutting 2.5" pieces of fabric to use as filters inside the facemasks. This is for the Montana Mask design (you can find our Modified Mask here: https://www.thingiverse.com/thing:4440610)
Simply use a pen or pencil inside the guides to create the cut lines and viola! A perfectly sized filter insert for your mask in less time. Definitely a useful tool if you are trying to make a lot of these quickly. We created 4 finger pads for you to hold down the guide while you are drawing. Multiple pads for multiple positions as you markup the mask.
This was designed to help us more easily create multiple filters sized for the mask. This would allow people to get more out of each mask. 1 mask could make anywhere from 4-6 filters, allowing them more use out of each mask.