coffee filters are a good way to strain your material. If you can and the situation requires it double up on them. As far as the spice being absorbed by the filter I guess some will but it would be a minimal amount really. if the material you have in your spice is base solution allwoing it to dry out and then doing a solvent wash works well. The base solution will clump together and will not be absorbed into the naptha. as it is not soluble in naptha it just gets in there as tiny bubbles that end up suspended in the naptha due to mixing.
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