The best bread for paninis has a sturdy texture and can stand up to the press without falling apart.  Use, Michetta, focaccia, baguette, rosetta, and more, including Another option is ciabatta bread, which has a large, open crumb that absorbs moisture well. This helps keep the panini from getting soggy while also ensuring that the bread is nice and moist inside.  Another good option is sourdough bread, which has a relatively thin crust that crisps up nicely in the panini press. If you're looking for something with more flavor, you can also try using a Parmesan or herb-infused bread.