I work for a newspaper and for several months we have had sporadic issues when it comes to making our plates for the press. By issues, I mean those including pages that suddenly print upside down with the text appearing backwards and other instances where the text and images on a page are partially cut off or jagged.
Today I pin pointed the issue, discovering it had to do with the way some of our advertisements are being made in house.
It appears that when our ad designers go to a third party image site (Creative Outlet, which we subscribe to), they are sometimes downloading entire ads (which include several .eps files) and then pulling one piece of artwork from the ad to use in an entirely different ad.
I was able to locate a particular piece of said artwork that was utilized in one of our ads this past week. It was a .eps. I, instead, re-saved it as a .jpg, then relinked the file in Indesign, where our in-house ad had been built. I then exported as a .pdf and then placed that .pdf in our newspaper layout and exported the entire document to .pdf.
When we went to "roam" the page/pdf, the page was fine, except this ad did not have this piece of artwork showing.
I then went back and instead of exporting the ad as a .pdf, I exported it to .jpg. I then brought it into our newspaper layout, and exported it to .pdf.
When we roamed this page, the page was fine AND the ad now showed up in its entirety.
So, my question or questions, is/are:
1. What are the differences between .eps and .jpg and why would their distinction have an effect on the RIP process or computer to plate process?
2. What are the differences between .pdf and .jpg and why would their distinction have an effect on the RIP process or computer to plate process?
At the end of this, what I really just want to understand is why did the process I eventually came to (saving .eps file/artwork as .jpg, then after placing it in my ad document, exporting said document as a .jpg) work?