The Save Image panel (opened using File... Save Image...) allows the contents of the graphics window to be saved as an image file.
When Maintain current aspect ratio is on, the image width/height ratio is constrained to match the width/height ratio of the graphics window (not including borders). Entering the width automatically adjusts the height and vice versa.
When Maintain current aspect ratio is off, width and height can both be set as desired. Grow to Fit resizes the graphics window to match the image aspect ratio by increasing one window dimension (i.e., width or height), while Shrink to Fit resizes the graphics window to match the image aspect ratio by decreasing one window dimension. If the window has not been resized to match the image aspect ratio (as specified by the values entered for width and height), a saved image will include more than what is visible in the display.
Save As opens a dialog for saving the image file; the possible formats are PNG, TIFF, JPEG, PS (PostScript), and EPS (encapsulated PostScript). Cancel dismisses the panel; Help opens this manual page in a browser window.
Background color can be changed using the menu (Actions... Color), the command set bg_color, or the Background preferences. If the system hardware permits, starting Chimera with the --bgopacity option will make the background transparent. TIFF and PNG images saved with a transparent background are easier to composite with different backgrounds in image-editing applications.
Smoothness can be increased by increasing the resolution (number of pixels). Additionally, independent of resolution:
Shininess of stick, ball-and-stick, sphere, and ribbon molecular representations, molecular surfaces, and surfaces generated by Volume Viewer and Multiscale Models can be adjusted with Shininess Control.
Lighting parameters can be adjusted in the Lighting tool.
The command copy is another route to saving and printing images, but cannot yield resolutions higher than that of the screen.
See the Images for Publication tutorial for examples of image creation.