Hello and Greetings.
I would like to know what is the best size and resolution for submitting stock image's? I have been setting my image's at 2400x3000 @ 300 DPI for selling on Red Bubble and Fine Art America. Is this a good size and what else is should I look for when submitting images to stock company's?
Best to sell at your camera's native resolution, or crop in (for composition), downsize (for quality) if necessary. You're generally not allowed to upsize in Micros, and you often get paid according to the size which is bought.
You may find that the inspections are shockingly strict, but you get used to that fairly quickly.
A lot depends on which agencies you're intending to submit to. Usually no people/parts without model releases, no logos, no contentious objects (where the manufacturer/artist might sue) etc.