weighed-in portion

if you are mixing in a tank, and the formula asks for assorted ingredients, weighed in to the tank. You must weigh to the provided tolerance. Not too much and not too little.

This is normally required for reactive components that have to be added in their stoichiometric amounts to make sure the reaction is complete, and there are no excess unreacted molecules.

things that are not critical are usually labelled qs, = quant suff = a sufficient quantity for the desired effect. Usually a color or perfume or thinner/thickener is addes qs.

enough to get the smell, color, thickness, etc desired on a personal level.