Laser photoplotting supports positive or negative images, crucial for inner copper versus solder mask layers
https://cashrvgd162.iamarrows.com/laser-photoplotting-services-vs-traditional-methods-what-s-best-for-your-pcb
Laser photoplotting supports positive or negative images, crucial for inner copper versus solder mask layers, giving fabs flexibility to match their resist processes and optimize contrast for clean edges.