I have a positive acting presensitized UV-curable PCB board (link). I'm using the manufacturer-provided developer.
Supposedly, the parts that get exposed will get washed away by the developer. However, I observed that my traces are always the ones that get exposed no matter what arrangement I do. It seems like the "minority" always gets exposed.
What am I doing wrong? Is this the normal behavior for photoresist PCBs? I'm always using the same developer all cases.