Because the color of the bottom layer can be revealed by covering the dye layer, this is very different from the effect obtained by any opaque painting. Before covering dyeing, ensure that the early color layer has been completely dried. If you want to directly cover the base painting with dye, you can directly draw the base painting with propylene pigment.
Oily topcoat, or all oil painting pigments, can completely cover the acrylic painting layer, but the acrylic pigment cannot adhere to the oily painting layer.
Extended data:
The basic process of painting conservation
First, clean up the picture
When preparing a clean solvent, we must first distinguish the strength of the solvent. Many solvents will seriously damage the materials used in the works, and sometimes even corrode the coating of the works, making the texture of the coating soft, such as acetic acid, ammonia water, amine butyrate and so on.
Commonly used solvents are: white alcohol for painting, pure turpentine, alcohol, acetone, benzene, xylene and so on. Many solvents can be mixed into two, three or even four kinds to be used together, and each solvent has its own characteristics and dissolution, which completely depends on the degree of material pollution and the tolerance of the work.
But no matter which way, the most basic thing is that the restorer must first test the cleaning function of the solvent in a corner of the work to make sure there is no problem before using it, so as not to cause regrettable damage to the work. The cleaning process is to dip cotton in the prepared solvent, smear it on the surface of the work and gently wipe it.
Gradually, it can be found that cotton turns dark yellow due to infection with Wannis layer or dust. Generally, it can be determined that cotton is clean until it is no longer contaminated with any stains, and at the same time, it must not harm the pigment. The success of cleaning depends entirely on personal experience and judgment on repair.
Second, fill in white pulp.
If the surface of the work is cracked, peeled off or damaged seriously, resulting in many holes, it should be filled with white paste to restore the flat surface. First, take a proper amount of water-based animal glue, heat it with waterproof heating method, and gradually add a little honey, phenol and hydrated lime, then apply the heated white paste to a hollow place and shape corresponding strokes around it. The filled white paste is white.
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