Printing: RGB - CMYK
So, a family member wants to print christmas cards that will most likely be created with the likes of Canva to send to their customers.
I have often read about CMYK colors being important to printing as RGB would result in reduction/quality loss of the colors as many printers can only deal properly with CMYK. We will most likely use an online printing service for this, however the question remains as to how to "make sure" that the png/jpg actually has CMYK colors?
How can I check that or make sure it does have this?