Priming is already the first layer of a finishing covering, it pursues two aims: to provide good adhesion of a surface with a paint and to reduce the expense of paint and varnish materials more expensive at cost. Structures used for this purpose name first coats, they consist of film-forming substances, napolnitelej and pigments. On sale there are first coats ready to the use. They are easy for making and most. Actually the first coat is more liquid oil koler in which drying oil prevails and the small amount approaching on colour and cheap painting substances contains. Under white colouring the blue ground, under brown the yellow suits. .
As the First coat can serve and pure natural drying oil, it does not form a continuous smooth film as its considerable part is absorbed deeply during a wood time. But at drying under the influence of oxygen of air of a fibre become firmer. Such consolidation does not occur at shpaklevanii without a preliminary first coat as dense shpaklevochnaja paste does not get deeply into a tree time. Emptiness remaining thus interfere with formation of an equal glossy colourful covering.
Oil first coats are unsuitable under glutinous colouring. Under nitroenamel coverings can be used both special nitrocellulose first coats, and the ordinary oil.