When making French toast, you want bread that's just thick enough for the bread to hold without becoming soggy or breaking but thin enough for the custard to be fully absorbed.

Taylor Ann Spencer of Delish claims that a 1” cut of bread is thick enough to absorb the custard but thin enough to cook quickly in the pan without burning.

A 1” thick piece of bread cooked for 3 minutes on each side at medium heat is just enough to fully cook the bread and create an even, creamy center and golden texture.

However, if you're preparing stuffed French toast, you'll want a slice of bread that's half an inch thick instead of 1” on account of all the toppings and fillings you'll be adding.