Lantern Slide storage envelopes are available in our four- flap style. This type of envelope looks like a “plus” sign. The lantern slide is placed in the middle and the four flaps are gently folded over it. Such a system prevents these old images from sliding in and out, as a conventional envelope requires, resulting in a safer housing. Four flaps for lantern slides are offered in .006 non-buffered and .007 MicroChamber papers. They measure 3-1/4 x 4 x 1/8″ and are sold in packages of 25.