I have align to pixels turned on for new objects, but an image I placed earlier is not aligned to pixels, though it’s exactly 1440 x 900. How do I set Illustrator so that when I move this image object, it will always snap to a round number?
Transform window, make sure
Align to Pixel Grid is checked. This will force things to snap.
EDIT Make sure you have a shape selected for the checkbox to work.
If that still doesn’t work, go to the
Transform menu and check
Align New Objects to Pixel Grid and replace your image.
Also as AdamSchuld mentioned, you can set this setting when creating a new document under the