Sometimes on the ceiling you can notice the presence of soluble salts, they lead to the formation on the surface of a white crystalline plaque, I also call it. The most common reason for this is the increased humidity of the room. To avoid this defect, the ceiling should be well dried, and then cleaned with special brushes. After cleansing the surface, it is again treated with plaster, and only then the layer of painting is applied. The surface must be darkened and primed. By the way, you know that a piping calculator has now appeared, which is very useful for those who do not know the exact price of pipes.
If the surface was painted according to the old layer of paint, without using primers, then the appearance on the ceiling of the “Ingasians” is possible, which are removed by blurring the old layer. And if the paint is not mixed properly, or use uneven pressure on the brush during painting, then the appearance of “stripes” cannot be avoided. Eliminate it by washing the defective area, and coloring it again. If on the stained surface there are many cracks that are processed using a gypsum composition, then it is necessary to primer with particular thoroughness, covering each gap, otherwise the appearance of the “veins” cannot be avoided.