There is a primary source behind all things read online, although it is not aways easy to figure out the primary source of information. We often have no idea of the origins of the stuff we consume online, especially when it comes to painting.
For example, if you were to take something I publish about painting and then add your own spin on it, you would be a secondary source and less credible than the primary source - which includes the study behind the source content.
I am the primary source behind everything I publish about painting (also called the original source or evidence).
And believe me, it makes a difference.
Note: Please do not Private Message me with questions that can be answered sooner by the rest of the Maximum Painting community. I cannot provide personal diagnostic or product advice via PM. Please utilize the community as your resource. Thank you!