3 Tips for Designing Around Facebook’s 20% Ad Text Rule …

Facebook’s advertising guidelines include a 20 percent text rule, meaning that the text on ad photos cannot take up more than 20 percent of the photo. We should note that this guideline is only specified for ads featured on the News Feed! If you’re planning on promoting a post or doing a News Feed sponsored story you need to follow this rule.

https://www.shortstack.com/blog/3-tips-for-designing-around-facebooks-20-ad-text-rule/