Has anyone done any work with writing PDF from an iPhone app?
I’m needing CMYK and RGB vector elements. Nothing complex.

There is a PDFKit from Apple that can be leveraged with declares. https://developer.apple.com/documentation/pdfkit

Don’t think anyone has implemented them yet though.

I don’t expect the classes from Apple on iOS to do CMYK.

Maybe work can be sent to a server, so you can use DynaPDF functions?
Sadly we have no iOS plugin SDK.

Actually sending it to a server to produce the PDF is a great idea. Thanks Christian.