I am looking for more explanation of tincturing math. The examples in the internal preparations videos are clear and precise but use very easy figures and a single plant tinctures. When I see a tincture blend that includes many tinctures and then one listed as Calendula 90%… I am unclear of what that means? An example would be the mouthwash tincture in the oral care section of herbal therapeutics. I am currently trying to find a copy of Making Plant Medicine by Richo Cech, but it is hard to find! I looked “inside” (online) and it looks as though he explains this math very thoroughly. It would be nice to run through more tincture math in reference to some of the tincture recipes in the therapeutics section. Is there any resources you could recommend with tincture worksheets etc?? When it comes to math… practice is necessary for me… many thanks… kim