I am trying to generate a print compatible layered PDF page. Currently I am using the CGPDFDocument to render the PDF file but it is not clear whether it is possible to create PDF layers - or Optional Content Groups (OCG) as I believe they are known.
Any pointers on how to do this ?
EDIT:
Some progress here -
Currently for the spot layers I am importing a PDF file page containing the required spot colour and scaling it to fill the required area.
For imported logos the logos are generated with the required spot colour - actually it is just a custom colour space with a specific label used by the print process. For example PMS 431C (Pantone)
Ideally I would like to be able to create this in code but I don't know how to create a custom colour space and then use the colour from that colour space. A different question perhaps.