This substance is yellow-black and is very viscous. It will not dissolve in water, and it is toxic if ingested. The material also has a strong odor, which will vary depending on the process in which is was made. Tall Oil is a natural byproduct of creating wood pulp, which means that the consistency and potency of each batch will depend on the type of wood used.
A good way to classify Tall Oil is to look at its acidity. Pine trees, for example, will yield a batch that has an acid rating of 160-165. If the pulp is a mixture of hard and softwood, however, then the acid rating will reduce to about 125 to 135.
Most wood mills that create Tall Oil will either use it in house or sell it as part of its revenue stream. The most common applications of this substance include: being used as a binding agent, creating rubber, emulsifying, and as an ingredient in certain inks. This substance can also be used in natural oil-based varnishes. Finally, Tall Oil can be used in drilling as an ingredient in the fluids used to lubricate the machinery.