Illustrator "Print to PDF" losing vector quality for small details

[cartographer29]

I've been using Illustrator to create graphics for pad printing processes for years, yet on occasion I will run across an issue where the smallest graphics will occasionally lose their vector quality and be simplified. So things like round circles become 4-5 point straight-line objects that loosely represent an O.

Now this is very small scale stuff, like 2.5mm square labels intended for fine-scale model making. The attached image shows how an information label loses its curved elements the smaller it gets. The intended size is the smallest one that you see.

Currently the setup is that the working files are kept in AI, and then the "print to PDF" function is used in combination with an invisible transparency in the file. This allows the AI files to maintain the working fonts while the exported PDF files to be outlined for export to the printer, which removes any possibility of font conflicts.

"Print to PDF" is preferred because it reduces the file size signficantly. Just saving the file as a PDF doesn't improve the vector situation either. I feel this is all related to the transparency used to outline fonts and strokes.

[Monika Gause]

Looks like an issue with the flatness setting.

But printing to PDF is really outdated.