I recently took maybe 15 old filters i had laying around and made a HUGE ball of GOLDEN concentrate.Many people use coffee filters for extractions, and you DO lose some to the filter.Anyway you can take whatever solvent you prefer and soak the filters in it for a couple of mins just up to the point where there submerged,i use acetone.Then you can use whatever method you prefer to evap the solvent and you will be left with killer stuff.I recomend squeezing the solvent out when you remove the filters, you can lose alot.Many people have TONS of old filters that would make a baseball of concentrate.I compared this stuff to some top shelf i had made. This stuff is CLEAN.Tastes good as long as you do the evap properly.No lab essay but if i had to guess maybe 80+ percent from the filters i ran by weight(I have tried many tested concentrates so i can give a semi accurate estimation )
Its not worth it for a couple but ik people with several hundred filters laying around lol .
I may post my tek in a few,but a friend of mine actually has a similar method and turns up similar results so any method you prefer is best. Yields very nice .