Before exposure, fabs verify plot integrity with AOI systems that compare the film to source data

https://siit.co/guestposts/choosing-a-laser-photoplotting-service-what-to-look-for-in-a-provider/

Before exposure, fabs verify plot integrity with AOI systems that compare the film to source data, catching broken traces, missing apertures, or polarity errors before costly imaging and etching steps.