Cloudscapes, Full Pane of 15 x 37-Cent Postage Stamps, USA 2004, Scott 3878 Self-adhesive stamps, featuring 15 different photographs of various cloud formations Cirrus radiatus, Cirrostratus fibratus + undulatus, Cumolunimbus mammatus + incus Altocumulus stratiformis / undulatus / castellanus + lenticularis, Altostratus translucidus Stratocumulus undulatus, Stratus opacus, Cumulus humilis + congestus, and Cumulonimbus Includes educational information about the cloud formations on the back of each stamp