Help reading flow rate calibration squares

H2D printer. 3rd Party PETG filament. I’m new to Studio. I’m having some trouble discerning which of these calibration squared is the smoothest. Not as obvious as I expected. I’ve tried the fingernail scraping test and visually looking withe magnifying lenses, still not very confident. The ones that I think should be over extruded have a matt finish, almost a chalky look. Not sure if that’s something to rule them out or not. I went with “5” for the first set. If anyone has any input on how to tell, I’d be grateful, see high res. photos I took in bright, diffuse, florescent lighting. On my browser I have to open the images in a different tab to see full resolution.

part 2 test:

I use a 10X magnifier to look for gaps or ridges between the lines.