people that prepare marketing materials, as a potential source

Scientific advertising and marketing is a small, specialized field, done by people with fairly solid technical backgrounds (we produce a whole lot of advanced STEM degrees, there's plenty of folks available with this sort of background).

So I just want to be crystal, crystal clear here: there's no way in hell anyone involved in this pipeline should have any confusion as to whether "improving" gel photographs by painting out details and/or copying and pasting blots is fraud. "Proofer" or not.