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. Verkkowhat does the evaporation line on a pregnancy test indicate? An evaporation line mimics a positive pregnancy test. A second line shows up when in fact you are not. Verkkounderstand the difference between a faint line on a pregnancy test that means you're pregnant and an evap (evaporation) line that is colorless and. Verkkoa vague result might indicate a very faint positive pregnancy test or even just an evaporation line. In this article, you’ll learn how to tell the difference. Verkkohere's how to tell the difference between a true positive pregnancy test and an evaporation line, plus tips for avoiding an evaporation line on blue dye or.