Ключевые слова: abstract, art, background, barrier, black, border, boundary, brown, cage, chain, construction, dark, design, drawing, element, enclose, enclosure, fence, graphic, grate, grid, grunge, illustration, industrial, industry, iron, isolated, keep, link, mesh, metal, metallic, old, paint, pattern, protection, safety, seamless, security, silhouette, steel, system, texture, textured, tile, urban, vintage, white, wire,