So i took a test, and within 3 min i noticed a VERY very faint line, so faint I couldn't tell if it had any color to it so I assumed it was an evap line. However, i did take a picture and made a negative of it just to see if it would still be there. And it is. So my question is, would an evap line be visible on a negative image since evaps arent supposed to have color to it? Or can the line on the negative image only show up if there was some color? Im basically just trying to be sure it was an evap line and not a vvvvf positive