Yinchuan seven-color pen training center. Yinchuan Seven-color Pen Training Center is a high-standard art training school, which employs famous art teachers to provide training for 8- 16-year-olds and offer sketch classes. Painting class, so Yinchuan 12-year-old children should choose Yinchuan seven-color pen training center school to learn sketch. Sketch in a broad sense, as the name implies, is "simple description", that is, using pencils, brushes, pens, carbon pens, and even the popular handwriting brushes to make monochrome descriptions.