Abstract: A picture frame assembly of trapezoidal-troughlike members with "U"-clamped miter joints has an inwardly projecting picture mount flange structure with adjacent tapered-section sides adapted for detachable picture-retention by "U" clamps of the type having lateral arms, and by nails in holes provided with axial clearance by staggered offset of outer sides of the frame members relative to the inner sides; an alternative hybrid type miter joint securance employs both "U"-clamp and screw fastener.