Change a file from 300 ppi to 300 dpi

[Lina22167546c3l7]

Hi! (Sorry in advance for bad spelling, english isn't my first language)

I've sent artwork for a record cover to the people who are supposed to print it. I've done this many times, the ppi of the pdf files has always been 300 ppi and it has never been a problem. This is a new printing company and they're saying the files have to have 300 DPI. Can i convert the files in any way (and is it really necessary)? 

The artwork is made on Illustrator for ipad but I have acces to the real Illustrator and Photoshop. 

Please Help!

[kglad]

<moved from using the community>

[Ton Frederiks]

Illustrator files are made with vectors and do not have a resolution.

Only images and raster effects do have a resolution (ppi).

The effects resolution can be controlled in the Document Raster Effects setting. The effective resolution of the images depends on the resolution they had when placed at 100% and the scale applied in Illustrator.

PPI and DPI are often used for resolution (although DPI was traditionally used for printers).

[Ton Frederiks]

I would check the file in Illustrator, for Raster Effects Settings and the effective ppi of images in the Links panel.