Ключевые слова: abstract, ad, advertisement, advertising, announcement, background, billboard, black, blackboard, blank, board, canvas, chalk, chalkboard, class, classroom, close, closeup, communication, concept, copy, dark, design, dirty, distressed, drawing, education, element, empty, frame, grey, grunge, grungy, horizontal, learning, message, nobody, old, pattern, rubbed, school, slate, space, surface, text, texture, textured, wall, wallpaper, white,