Are you talking about for presenting your images on another computer? If so, figure that the majority of the users online are working with 800 x 600. Some artists use higher. I use 1280 x 1024, (and 1024 x 768 at work... older monitor) because I like to see more on screen. (plop render's my friend) So, if you are presenting art to someone else, whether it be over the web or not, try to keep your image within the 640 x 480 dimensions. That way, it's sure to fit into the window, and when the user opens your image, they don't just see the top left corner. Unless that's all you want them to see, and you are hopeful that they will tolerate scrolling to see your pic. For me, if I have to scroll around the pic, I don't enjoy it as much no matter how good it is. And if I have to scroll side to side... forget about it. Putting the "best viewed at x resolution" on the page is an absolutely useless endeavour. Honestly, when was the last time you changed your screen resolution to view a page or an image? If you're like me, the answer is never (Star Wars trailers excepted). Some users can't even res up to 1024 x 768. Some have slower video cards. Some have older monitors. What if the user has an LCD monitor and 800 x 600 is all they can do clearly? So, though you may not be inclined to make separate versions of your work for lower res viewers, I think you'd do well to use Photoshop (or equivalent) to size down your pics for on screen distribution. Your viewers will spend more time looking at your work, they will load faster over the web, and you can always provide a larger resolution version for the truly interested viewer that wants more than 640x480. I hope that's what you are asking. And Agent Smith is dead on about color. Windows is a bit behind in color calibration as it is, and when you add in all the crappy displays out there... it's a jungle. If only there was a fix for the crappy monitor....