In general, most types of varnishes or lacquers can be sprayed using the appropriate needle size based on the product's viscosity. A 1.3 to 1.5 mm needle is typically suitable for transparent varnishes, but the varnish may need to be slightly thinned to achieve an even application. 

Different types of varnishes for furniture or floors can be sprayed without any issues. If the varnish or lacquer dries too quickly, a retarder can be added to the product. However, achieving a successful finish requires considering working conditions, such as controlled temperature and humidity, as well as the surface's temperature being sprayed.