Hello, took a test this morning and thought I caught a glimpse of a line at an angle but cannot see a thing top down... so I opened it up. Is it possibly a positive, or do these things have a kind of texture to the test line that means angling it like this makes it look visible when it shouldn't be? The line is basically only visible when the surface is reflecting light, so it just has less shine to it, rather than being coloured. It might be wishful thinking...