What's your standard file dimensions?

[Maeflower]

I was just going to start a new sketch and had a curious thought: is there any standard image size and resolution with concept art?
What pixel dimensions do you guys use? Or do you go by print size? What about resolution?
I know certain jobs require specific dimensions, but I'm just thinking in terms of standard, everyday stuff. I was thinking, something like 11×17 in. at 150 dpi. (comes up to 2550x1650 pixels)
Of course the other question is color. Should I start out in RGB or CMYK? What bit depth?

[Ian Barker]

I usually start with the default Letter setting in Photoshop (8.5x11 at 300dpi). Obviously if you have a print job you will want to get the info on dimensions from your client. 300 is the most widely accepted resolution, but it can depend on what you are working on. Anything above 300 is an unnoticeable difference in nearly all cases (I actually don't know of any reason to go above, but I'm not for sure). If you are printing use CMYK, otherwise RGB. I've never played with bit depth, default should be fine though.