Primers should have good adhesion to different surfaces, both new and previously treated, providing a good foundation for proper coating material. Primer smooths the surface tension coating, thus covering material will be better adhered (attached) to the substrate. It is quite difficult to put a finishing coat on a new old covering as a tool to easily inflicted material glides over the surface. Primer adequately provides roughness foundation for the successful application of topcoat. Compared with a topcoat, a primer often have higher content of dry residue and, consequently, they have a higher occupancy of that better hides minor imperfections. Nevertheless, for high quality paint finish is very important to carefully prepare the ground, as paint can not hide surface defects and the defects on the contrary clearly stand after the finish paint. Primer dries quickly and is easy to grind, which is important in preparing the surface. Inflict paint over the primer compared with a topcoat can be faster and, therefore, in this case to save time.
Hiding power of a good primer, usually even better than the coverage topcoat. Nevertheless, it is better tinted primer close to the tone with an effective layer of tint to cause a smaller number of layers during the final painting. In most cases, one application of primer and topcoat for well-covered and smooth finish. Primers reduce the absorption of the surface. There are big differences in absorbency of substrates. Especially porous gypsum-based fillers and powder filler of cement-based have a relatively high absorption, while at the drywall sheet on the cardboard sections absorption is low. If the absorption of the surface before painting is not aligned with primer, then a finishing layer is more opaque in the joints, containing filler with a high absorbency. If you are using is not absorbing primer decreases the absorption of the substrate. If such a surface to paint, then application of the primer increases the duration of work with a topcoat, which in turn will contribute to more easily achieve a uniform result.