You're viewing part of a thread.
You're pushing it through one system that converts a PDF file into printer instructions, and then through another system that converts printer instructions into a PDF file. Each step probably has to make adjustments with the data it's pushing through.
Without looking deeply into the systems involved, I have to assume it's not a lossless process.
Those printer instructions are called Postscript and they’re the basis of PDF.
You are thinking that the printing process will rasterize the PDF and then essentially OCR/vector map it back. It’s (usually) not that complicated.
Unless of course you print everything and then scan it again, like this guy probably does.
You should maybe look a bit more into it. How do you think commercial printers or even hobbyists maintain fidelity in their images? Most images pass through multiple programs during the printing process and still maintain the quality. It’s not just copy/paste.
Magnum PI over here hittin em up with the facts.
They maintain a high quality but not lossless.
As a trivial example, if you use the wrong paper size (like Letter instead of A4) then it might crop parts of the page or add borders or resize everything. Again I'll admit, in 99% of cases it doesn't matter, but it might matter if, say, an embedded picture was meant to be exactly to scale.
Lossless is the default for print output.
My friend, I worked in commercial printing for 2 decades. You’re still making assumptions that are wrong. There are ways to transfer files that are lossless and even ways to improve and upscale artwork. Why do you care so much about this?
"There are ways" ≠ this is what happens by default when done by the average user