Incorrect output when Exporting as a PDF - Illustrator 28.6

Was the original artwork created in Adobe Illustrator? Are the original elements vector based?

The PNG format is a pixel-based image format. PNG does not support vector-based elements. It typically defines images in RGB color space. PNG is not an ideal format for print work. JPEG is another pixel-based image format. JPEG can support RGB and CMYK color modes, but it doesn't support print-able vector artwork. It's possible to save a copy of a Photoshop layout that has vector work paths in JPEG format and still preserve those paths in the JPEG file. But those kinds of vector paths are not print-able. They're just paths to use to turn into selections and other stuff.

If the poster design is going to be printed the design should have colors that are within the limits of CMYK color space. If the print company has special printers that use extra inks (such as light cyan and light magenta) the color intensity can be pushed a little farther.

PDF is usually the best format to use for print purposes. PDF will preserve any vector based objects in the design. PDF has native support for transparency effects. PDF files saved by Adobe Illustrator can have Illustrator data appended to them. Many print shops will use RIP applications that include Adobe certified PDF print engines. They'll be able to handle unique effects from Illustrator, such as gradients on line strokes and free-form gradients.

Hello @18274928,

Thanks for reaching out. Would you mind sharing more details, like the version of OS/Illustrator, details of your workflow, and a public link to a sample AI and PDF/JPEG files after uploading them to Dropbox/Google Drive/etc., so we can better assist you?