Brilliant article, thank you. One question though — what we’re producing here is an appropriately sized file at 72dpi. Printers often request 300dpi files. In that case would you:
a) Export the final version of your design at 4.166x scale, resulting in a file with 4x larger physical dimensions than the finished product will actually be. Would this larger (in dimensions) file qualify as 300dpi?
b) Set up your initial artboard at 300dpi dimensions — i.e. 4x6" would be 1200 by 1800 pixels according to this online calculator — and then export your final version at 1X. Same results as above except you can ensure that any bitmap images are not pixellated before you export the finished product.
c) Use a different program that will export a file in the correct physical dimensions, yet at 300dpi resolution instead of 72dpi.