Description
Tempera ground is formulated with a polymer emulsion of vinyl acetate-ethylene (VAE) and high pigment volume concentration (PVC) of titanium dioxide, calcium carbonate, and wollastonite to produce an easily sanded and absorbent surface. The surface of the ground is very absorbent and formulated explicitly as a ground for tempera painting, providing a surface ideally suited for egg, casein, and collagen (distemper) tempera paint.
Product Application
Only use on rigid substrates such as hardboard, wood, or metal panels. Potential for cracking may occur on highly absorbent surfaces and flexible substrates, like a stretched canvas. Check for adhesion on non-absorbent surfaces before use.
Apply in multiple thin layers, gradually building up to the desired thickness. Single thick layers could crack upon drying. We recommend applying at least four coats.
Sanding
When sanding, follow these general guidelines:
Allow Tempera Ground to dry completely before sanding. Cured films are more accessible to sand.
Start with coarser grit sandpapers, then finer grits until the desired smoothness is achieved.
Both wet and dry sandpapers may be used.
Wet sanding generates less airborne dust and produces a smoother surface than dry sanding.
Sanding to a glossy (polished) surface can reduce the mechanical adhesion of paint films. As always, test your application.
Upon completion of sanding, use a damp, soft cloth to remove sanding dust particles from the surface. Failure to do so can cause poor adhesion.
Diluting
Brushing: This product may be diluted with up to 20% water for easy brush application.
Spraying: Dilute Tempera Ground with Rublev Fluid Medium. Begin at a 3:1 ratio (Ground:Medium) and test spray quality, as various spray equipment may require additional thinning. Further reduce viscosity by adding up to 20% water.
Support Induced Discoloration (SID) Protection
Support-induced discoloration, or SID, occurs over a relatively brief period as the media is drying. The discoloration can occur in any acrylic media or gel brand but is most noticeable in unpigmented gels, matte, and gloss media. It can, however, also affect specific colored paint and incredibly transparent layers of blue.
To reduce discoloration of the ground and paint layer caused by Support Induced Discoloration (SID) when applying acrylic paint on supports that contain water-soluble impurities, such as canvas and wood, first apply two coats of Rublev Colours Fluid Medium and allow to dry thoroughly. Then, apply the desired number of coats of Tempera Ground.
Oil Painting Substrate Protection
Tempera Ground is designed for tempera (egg, casein, collagen) paint. Its high absorbency may cause sinking in of oil paint, especially dark colors. If used as an absorbent ground for oil paint, canvas and paper substrates should be protected from vegetable oil fatty acids. To protect natural fiber substrates, follow the above instructions for SID protection. Allow sufficient time for the ground to cure before applying oil paints to maximize mechanical adhesion.
