Comment 4 for bug 1680527

Did you look at this picture and think everything should look the same, the copper, the pcb, etc?
https://s-media-cache-ak0.pinimg.com/originals/1f/8c/a1/1f8ca1e108fb9513c283ac32e6c0215f.jpg

1. the soldermask gets rid of the fiber pattern see: http://kingofwallpapers.com/pcb/pcb-005.jpg
2. The majority of the PCBs are made such that the copper shows no PCB patterning see: https://stab-iitb.org/electronics-club/assets/using-eagle-to-design-pcbs/image03.jpg

This patterning should be removed from everything but the actual exposed by soldermask opening area.
The liquid soldermask pours over the pattern and covers it up. The copper from all the PCBs that I've seen either has a VERY VERY TINY patern to it or no discernable pattern at all. Gold, tin, or other process plating gets rid of the pattern completely! The solder paste mask will also cover up any pattern from anything.