Most covers aren’t seen in a bookstore but as a thumbnail — tiny, among dozens of others, on a phone screen. A design that shines as an A4 print can vanish entirely at that size. Good cover design therefore starts with a question: does it work small?
Legibility beats beauty
The title has to be readable at 120 pixels wide. That means generous type sizes, high contrast, few words. An elegant but delicate wordmark loses to a bold, clear one every time — not because it’s worse, but because nobody can decipher it.
A cover you have to enlarge to understand has already lost.
The genre speaks too
Every genre has a visual language. Thrillers are dark and typographic, how-to books clear and trustworthy, romance warm and figurative. Breaking these codes is risky: readers scan for familiarity. A cover that doesn’t signal its genre is simply overlooked — no matter how artful it is.
Title readable at thumbnail size
Contrast that holds even on light backgrounds
Serve genre codes deliberately, don’t ignore them
One clear focal point instead of three competing ones
Iteration is the advantage
The biggest lever isn’t the perfect first cover but the ability to test ten variants. Those who can iterate fast — different type, different focus, different color — find the design that clicks by trying rather than guessing. This is exactly where automation shifts the economics: what used to cost a hundred euros per variant becomes a matter of minutes.