If you've printed an image with a gradient in it, you're probably familiar with banding (a visible line where one color ends and the next starts, like bands of color, instead of a smooth transition from one color to the next). There's a very popular tip for getting rid of banding that's very effective for high-resolution imaging. Open the image in Photoshop and go under the Filter menu, under Noise, and choose Add Noise. When the Add Noise dialog appears, for Amount enter 2, for Distribution choose Gaussian, turn on the Monochromatic checkbox, and then click OK. You'll see a little bit of this noise when viewing the image onscreen, but when printed at high resolution, the noise disappears and hides the banding. We add noise to every gradient we create for just that reason.