Is a faint line on a drug test a negative result?
Yes. It is very important that a line in the test region (no matter how faint) must be considered a line, and must be considered negative. This is how drug testers in Australia are trained.
This is the most common question we receive. The colour, or density of the line have no meaning on the drug test. This answer was backed up by our manufacturing engineers.
As you can see by the picture A below, there are variations in line densities. This does NOT mean that there could be traces of the drug in lighter lines.
Picture B has a non-negative result for AMP Amphetamines as there is no line at all, and must be confirmed either positive, or negative by pathology.