I'm still working my way through my e-mail and comments. I'm currently on Novemer 19th for comments and in early November for mail. Thank you for your continued patience. 

In this post, Preservatives, tafchk asks: How do you know how many drops to use for a given percentage please"

The short answer is that we don't use drops in our recipes or products, so I don't know that information.

We don't use volume measurements like drops for our ingredients - like preservatives, cosmeceuticals, essential oils - because it's simply too inaccurate. Is that drops from an eye dropper, a large eye dropper, a large or small pipette, an orifice bottle, a dropper bottle like the picture, and so on" Drops aren't the same out of each container, so to tell you that 10 drops of liquid Germall Plus is equal to 0.5 grams would be completely wrong because that only applies to my eye dropper, pipette, or bottle.
Viscosity plays a huge part as well. Every oil is slightly different than the next, so to say that every essential, fragrance, or carrier oil is x drops to 1 gram is incorrect. Avocado oil is much thicker than fractionated coconut oil, and you'd end up using too much or too little even if we were using the same dropper.

Lest you think this isn't a big deal, there are a few huge problems you'll encounter if you want to measure in drops. The first is accuracy. If you're dealing in drops for essential oils, you could be using too much or too little of what you want. Y...