How to Change the Resolution in Adobe Illustrator
Developed by Adobe Systems and included in its Creative Suite of design and development software, Illustrator supports the creation of graphics such as drawings, charts, graphs, cartoons and other illustrations. Because the program saves design elements in a vectorized format that scales to any size, you cannot change the resolution of an Illustrator file directly. However, if you choose to export the content of a file to an alternate format, such as JPEG, Illustrator gives you the ability to specify your preferred resolution.
Open in Adobe Illustrator the file you want to export.
Click "File" in the top menu bar and select "Export."
Select in the resulting dialog box the folder where you want the exported file saved.
Give the file a name within the "File Name" field.
Click the "Save as Type" drop-down menu and select your preferred format.
Click the "Depth" drop-down menu within the "Resolution" section of the screen that follows and select "Custom."
Enter your preferred resolution value in the "Custom" field.
Click "OK." Illustrator will export your artwork to the selected format, at the selected resolution, within a few seconds.