Final size changes everything
A file that works at 24 inches may fail at 96 inches.
Resolution guide
Large-format printing does not reward guessing. The only useful question is how much real detail the file keeps once it is stretched to the final banner size.

A file that works at 24 inches may fail at 96 inches.
Banners read from farther away can tolerate less detail than close-view photo prints.
Small text, dense graphics, and detailed photos need stronger source files.
The phrase resolution for large print can be misleading because it suggests there is one magic number. There is not. A bold headline banner and a sponsor-heavy event wall do not need the same file strength.
What matters is the effective quality at the final dimensions. A file with enough detail for a 3 x 6 banner may look weak when pushed to 4 x 8, especially if it includes small type or photo detail.
Usually the most forgiving if the source logo is clean.
Can work well, but close-up faces reveal softness quickly.
Often the least forgiving because thin or small text shows weakness fast.
Ready to print
Upload your design and check how it behaves at the banner size you actually want to print.