Common HD Display dimensions in pixels:
1280w x 720h, 1366w x 768h, and 1920w x 1080h
All the signs listed here have a 16:9 aspect ratio and are for widescreen displays. Another common ratio is 4:3 for letterbox displays.
Most signs on Miami’s Oxford campus are 1920 x 1080 but double check your sign before you start creating content for it.
For most signs, save your images for web resolution at 72ppi (pixels per inch). If you are using a monitor with retina display, consider increasing the ppi to 192.