Yes, compression bags really, truly save space. The larger the item, the larger the potential space payoff. Think of compression bags and sacks as packing tools that can shrink unwieldy space-hoggers to a fraction of their size, depending on the material. Even compressing itty items like swimsuits, travel dresses, shorts, and blouses is beneficial—it creates more negative space for bringing extra stuff or stashing vacation purchases. Just remember that compression bags save space, but don’t cut weight.