Solvents give the varnishes a liquid consistency. Varnishes are transparent and clear. They have a pungent smell of a solvent and high viscosity. Lacquer coatings are glassy and transparent. Depending on the resin and plasticizer used for the varnish, the varnish coat may be hard and resistant or brittle and not resistant to external factors. The degree of resistance to these influences determines the classification of varnishes (for indoor and outdoor use). Varnishes, the so-called. skinny, that is, containing a predominance of resins, are generally quick drying, varnishes, on the other hand, with the opposite ratio of ingredients, i.e.. greasy - they dry slowly. In terms of chemical composition, varnishes are divided into: oil, nitrocelulozowe, spirits, bituminous. Besides, there are so-called. special varnishes: acid-resistant, insulating, fireproof, waterproof, matting. Colorless oil varnish "20″ for internal works. It is a resin-oil alloy on natural or modified phenolic resin and on tung and linseed oils, diluted to the required consistency and activated. Dries hard, it is extremely resistant to abrasion and water, withstands a severe test of adhesion. It has a color no darker than the color 1/20 a normal solution of iodine in potassium iodide. Slight haze is acceptable. The coating at a temperature of 18-22 ° C is already over 24 at. hard and dry. It is used on wood previously primed with varnish and not exposed to weather conditions (walls, furniture and objects made of wood).