It is hard to say, I know I always found Crystal Clear really bad for evap lines, and normally found if there was no colour it was a BFN, even though there was such a distint line/shadow there. My best advice is to look at the start of each end of the result line, and see if there is any colour there at all. I found even the BFN's looked blue when holding them up to the light...I really hope it is a BFP for you though!!!