Bag comprising matching closing sections actuated by a slider

The present invention relates to a bag comprising two generally parallel sheets (16, 18) forming the main walls of the bag, complementary closure profiles (20, 22) fixed respectively to these sheets and a slider (50) for actuating the strips (20 , 22) in the closing and opening, characterized in that it further comprises, parallel to the closure strips (20, 22) between said sheets (16, 18) and at the mouth ( 12) of the bag, additional means in relief (100) designed to provide sealing by forming a barrier between the sheets (16, 18), bag from the closed position, said additional means in relief (100) being placed facing flanks (52, 54) of the slider (50) to be urged towards their sealing position by the slider (50) when the cursor is moved to the sealing position.