Picture frame and sheet blank therefor

A picture frame blank made of flexible sheet material foldable to form a picture frame, the blank comprising a central rectilinear base section, a first pair of opposed peripheral side sections extending from said central base section, a second pair of opposed peripheral side sections extending from said central base section, scored fold lines defining a boundary between each of said peripheral side sections and said central base section, a plurality of fold lines on each of said peripheral side sections defining inner, middle, and outer segments extending respectively from said central base section, said segments configured to be folded inwardly forming three dimensional side elements, said inner and middle segments of said second pair of opposed peripheral side sections including outwardly projecting extension flap members, scored fold lines acting as a hinge between each of the said segments and their respective extension flap members, said extension flap members being overlapped by said first pair of opposed peripheral side sections when all the peripheral frame side sections are folded into three dimensional side elements, said extension flap members prevent unsightly corner gaps between adjacent said three dimensional elements, and adhesive means for securing said three dimensional elements to said base section, and picture stop means on the base section for engaging and confining the picture in proper position therein.