A soft shell suitcase is useful when you go on vacation with the car. A suitcase that's soft can dent slightly. This way, the shape adjusts itself to the surroundings and you van easily stack multiple suitcases in the trunk. There are different sizes of fabric suitcases, like soft carry-on suitcases, medium suitcases, large suitcases, and XL suitcases. Which size you need, depends on your journey. Most fabric suitcases have convenient front compartments. That way, you can keep your passport and other documents easily accessible.