Abstract: Polythene bags are used to group together articles of clothing for transit. The invention relates to a security seal for use with such bags to prevent undetected transit theft. The seal according to the invention has two strip-like portions, which are formed with latching portions at points along the lengths of the strip-like portions. The seal is applied to the neck of the polythene bag, and during application the latching portions pierce the bag and pass through to engage in pairs with latching portions on the other strip-like portion. The latching portions have a weakened section, which breaks if the latching portions are urged out of engagement, thus a bag once sealed cannot be opened undamaged, as the seal will have broken latching portions indicating to a checker at the destination that the bag has been interfered with.