How to control the relationship between black, white and gray in sketching still life.

This is what I saw on the Internet. I hope it can help you adjust the relationship between black, white and gray in the whole picture, and can effectively solve the hierarchical problem of the picture, the volume relationship of objects, the relationship between main objects and secondary objects and the surrounding environment. Make the relationship between pictures clear and the texture of objects well expressed. How to deal with the relationship between black, white and gray in the picture? (1) squint at the overall light-dark relationship. Simply divide the black, white and gray parts into three parts, roughly arrange the black and gray parts together, and then spread another tone on the black part with lines at different angles (the first part is made into a small acute angle, which not only changes but also unifies the general direction of the lines). In this way, a simple black, white and gray scale came out. (2) Keep your eyes open, but don't look at the parts. Look at the light and shade, not the part. In this way, the levels of black, white and gray are refined to the tonal level, and then a single object is depicted. (3) Depicting a local single object, grasping and making up at the critical boundary of light and shade. The place where shadows meet objects is also darker. Highlight the outline and three-dimensional sense of the object. Describe the details and main points carefully. For example, the bottle mouth, the concave part of the upper part of the apple. The thin part should be drawn with a sharpened and slightly hard pen. (4) In the process of painting, we should constantly take a step back to see the overall effect. Pay attention to the overall color block. For example, no matter how dark the dark part of white cloth is, it can't be as black as the dark part of black cloth. (5) The unimportant part in the distance, that is, the imaginary part we often say, should use light and loose lines. Clear lines should be used for the main part and the real part in front. Hard and smooth, straight and clear lines. Like stainless steel and so on. Rough texture, like pottery. Loose thread and thick thread are ok. (6) When adjusting the map, first observe the darkest place of the whole group of still life, draw enough, then find the brightest place and use an eraser to brighten it. The colors in other places are based on these two colors to enrich the picture. When processing, you can enlarge the contrast of its tone and make its picture loud. Black, white and gray are the results of not getting through: gray-only paying attention to the part and ignoring the whole idea, all parts are too uniform, and the basic relationship between light and shade can not get through. Dirty-lack of overall contrast, there is an isolated black spot in the bright part, or there are several too bright spots in the dark part, or the light and shade are not well connected, or the lines are sloppy.