Ключевые слова: background, backgrounds, brown, building, chemical, circle, connection, construction, cylinder, energy, environment, factory, flow, gas, grunge, heap, horizontal, illustration, industrial, industry, iron, large, line, metal, metallic, old, pattern, pile, pipe, power, rust, rusty, shiny, stack, stainless, steel, strength, structure, surface, texture, transportation, tube, wall, weld, welded, welding,