Bill, thanks for the comment, When a surface color is difficult to read, most likely when dark or shinny colors or round surfaces are present, we suggest going with a laser type sensor like the WTT12L-B2561 made by Sick. This one performs way better with those challenging surfaces, but on the flip side, the sensor does not have the built-in time delay function that we use for the film overwrap adjustment. To address this lack of adjustability, if needed, based on your control panel type, we can provide you with an external time delay relay and corresponding wiring & connection diagram. Do not hesitate to call in if you would like more details.