Verkkowhat is an evaporation line on a pregnancy test? How does an evaporation line compare to a faint line on a pregnancy test? How can i avoid an. Verkkoan evaporation line on a pregnancy test is a faint, often colourless, second line that can appear on the test strip after the recommended reading time. Verkkoa faint positive is a slight, faint line with color (usually pink or blue) that appears in the results window of your test. Unlike an evaporation line.