Thought of this some time ago -- not sure if regular coffee filters made for your home kitchen counter are made from cotton or just wood pulp. However they are relatively strong even when wet. They are obiously quite porous, just tried holding one up to a light, --- so would hold lots of patch lube. Should not be anything in them chemical wise ( I hope ! not good for drinking the coffee --
). Not overly abrasive -- remember should hold lots of lube, -- and don't believe any fillers such as clay put in typing / printing paper. Available most grocerie stores - reasonable priced.
I tried wrapping last night -- took one of the white bleached ones, the type with the curly sides, come in a stack of 100. Pressed it out flat on the kitchen counter and drew appropriate spaced lines with ruler --- then used my homemade template to draw several patches, and cut out with scissors. When wet with tap water the patch becomes instantly nearly transparent and limp, but still easily wrapped over 45-70 cast bullet without tearing even with pulling gently to wrap with some tension. When the few I tried wrapping and left on floor heat outlet dried an hour later, seemed to hold together with the two layer wrap just fine.
The only negative so far, besides being a relatively small circular shaped piece of paper to work with, is the sidewall wrinkles. Tried taking one and laying out on plastic kitchen countertop and wetting with water to get to lay flat. Took paper towel and patted out excess water and made sure laying flat with no wrinkles -- let dry. After couple of hours -- much easier to work with flatter piece of paper. It looks like with one filter you could get about 10 -12 patches for a 45 cal. bullet.
Now to try loading and shooting them for evaluation....
---Nice group there Kurt !!
Happy hunting and shootin ... Bob.