Block Bottom Sick Bags have welded seams and a thin polyethylene lining like the Standard Sick Bags, but they are also manufactured with a Block Bottom and Fold-Over Fastener at the top. Consequently, they can be opened up and stood upright on a flat surface - and the top can be folded over and secured with the fold-over fastener after use. This doesnt make a secure, water-tight seal but it does help to contain the contents, reduce the smell and make a more manageable package for disposal... Block Bottom Sick Bags measure approximately 12cm x 22cm (5" x 8.5") when folded flat and the mouth of the bag measures approximately 8cm x 12cm when the block bottom is unfolded. However, the mouth of the bag can of course be opened wider to make a much larger target to aim at by pulling it into more of a circular shape.