Resolution and Document Dimensions
I don't get it. I've never really done much printing and I've not been using photoshop for long so I guess it may be one reason why it's not come up but here's my question:
In Photoshop when I go to make a new document I can set the document size in mm/inches or pixels. Then I can pick resolution.
Let's say I pick my image dimensions in mm, specifically 210mm x 297mm (the size of A4 paper, because I might be printing it out).
What effect does changing the resolution have on that?