I just got commissioned to draw up a poster for a good friend of mine who is starting his own business. It's going to essentially be a big digital painting, something done in painter or photoshop or the like and eventually it's going to be printed up door-poster sized. So somewhere around 21x62 inches.
So I was wondering if anyone could help me work out what a good DPI/resolution it would be to work in so that I can print an image that big at decent quality? I've never printed anything bigger than a mouse-pad so I have no idea what kind of filesizes I need to create for this. So if anyone has any help here I'd REALLY appreciate it as I have a tight deadline and need to start asap.
Thanks in advance. :)