GOLDEN Gesso is a flexible liquid ground that seals, protects, and gives "tooth" to substrates, which promotes paint adhesion. It is formulated to accept a wide variety of media on many commonly used painting surfaces. It comes ready-to-use, but can be mixed with water for thinner applications. When applied in thin layers, GOLDEN Gesso will conform to a variety of textured surfaces.
GOLDEN Gesso is available in Black or White, and can be mixed with GOLDEN Acrylics to produce a range of colored grounds (see below).
- Application Methods
GOLDEN Gesso can be brush, roller, trowel or spray-applied. Dilution of the Gesso is only necessary for spray application, but may be desired for brush or roller applications as well. When diluting with water, we recommend a maximum dilution of 25%. Any mixture within this range offers little risk of cracking or other adverse effects.
- Mixing With Other GOLDEN Products
GOLDEN Gesso can be tinted with GOLDEN Heavy Body Acrylics, Fluid Acrylics, Matte Fluid Acrylics, or High Load Acrylics. The High Loads most closely resemble the Gesso since they both possess a high pigment load, a velvety, low-gloss sheen and a similar viscosity. Matte Fluid Acrylics are the best option after the High Loads. Tinting with High Loads is recommended since they will alter the attributes of the Gesso the least. Due to the high pigment/solid concentration, High Load Acrylics and Gesso should only be applied in thin layers. Thick, single-applications of these products may crack.
Generally, canvas coated with GOLDEN Gesso may be rolled up without cracking. Cracking may occur if a canvas is overly flexed or stretched, especially at colder temperatures. For more information about handling and transporting paintings, please refer to the Just Paint Newsletter, Issue 11, article Safe Handling and Transportation of Acrylic Paintings http://www.goldenpaints.com/justpaint/jp11article1.php.
- Multiple Coats
Although one coat of Gesso will provide good adhesion, it may sometimes leave pinholes or uncovered areas. It is recommended to apply at least two coats of Gesso to any surface, but especially when painting on canvas or linen. The first coat will penetrate the support and reduce the likelihood of paint de-lamination. The second coat bonds with the first layer and begins to even out the surface. Subsequent layers of Gesso will produce an even smoother surface. For spray-application, you may have to apply more than 2 coats to achieve a film similar to a brush application.
- Spray Application Dilutions
The degree to which the GOLDEN Gesso needs thinning depends on what type of spray equipment is being used. No dilution of the Gesso may be required when using equipment with relatively large orifices and substantial pressure. Thin Gesso for spraying by blending with GOLDEN Airbrush Medium, which reduces viscosity, improves flow and tip-dry, and promotes leveling. Start with a mixture of 1 part Airbrush Medium to 1 part Gesso and test spray quality. Additional reduction with the Airbrush Medium may be required, especially with smaller nozzle equipment and lower air pressures.
While sanding GOLDEN Gesso is possible, the heat generated in the process will â€œgum upâ€ the sandpaper rather quickly. Wet sanding will give very good results while reducing dust production. For optimal sanding results on inflexible supports please refer to our Product Information Sheet for GOLDEN Sandable Hard Gesso: http://www.goldenpaints.com/technicalinfo_sandable
Use With Oil Paints
Oil Paints can be applied over acrylic Gesso. There is adequate adhesion due to the porosity of the acrylic. To control the penetration of linseed oil into support fibers, a two coat-application of GAC 100 is recommended before applying Gesso. This seals the substrate and greatly lessens the amount of oil penetration.
GAC 400 can be applied to canvas to stiffen the support before Gesso application. The GAC 400 will provide a stiffness similar to rabbit-skin glue while remaining insoluble in water. (Refer to the Information Sheet: GAC Specialty Acrylic Polymers for further information on these products).
By adding a gel or medium to gesso, one can increase flexibility and lower tooth and absorbency. GOLDEN Gesso can be modified with most GOLDEN Gels & Mediums. However, GOLDEN Soft Gels will least affect the feel and thickness of GOLDEN Gesso. Test mixtures to achieve the desired tooth and/or absorbency for each application. Adding GOLDEN GAC 100 (a thin, multi-purpose specialty acrylic medium) will reduce viscosity (product thickness). This results in a film that is thinner, stronger and more flexible. Additions of more than 10% GOLDEN GAC 100 will lower tooth and opacity of the gesso.
Increasing Tooth or Altering Texture
Tooth can be increased without affecting flexibility or crack resistance by adding GOLDEN Coarse Molding Paste, Coarse and Extra Coarse Pumice Gels, and other mediums and paints that may contain coarse solids. These additions will often create a much thicker product and different application techniques will be required, such as spreading with a palette knife or similar tool. Textural gels and pastes produce unique surfaces on which to work, and along with other grounds, such as GOLDEN Acrylic Ground for Pastels, can also be applied over the Gesso, or used alone as alternative grounds.
Resin: Methylmethacrylate/butylacrylate copolymer dispersion polymer
Pigment Identification: PW6 (White Gesso); PBk7 & PBk11 (Black Gesso)
Lightfastness: Lightfastness rated I (per ASTM D 5098)
Opacity: 1 (1=most opaque and 8=most transparent)
Viscosity: 3,000 - 4,000 cPs (as measured on a Brookfield RV viscometer)
pH: 8.4-9.0 (slightly alkaline)
Gloss: White: 5.0-10.0; Black: 1.5-5.0 (using a 75Â° Glossmeter)
Flexibility: ASTM D522, Test Method B-Cylindrical Mandrel Test at 70Â°F, 6 mil thick film passes at 1/4" diameter mandrel. Adequate flexibility to withstand loose rolling and re-stretching at room temperature. Paint films become more brittle below 50Â°F, and should not be bent, stretched or flexed under such conditions. Withstands expansion and contraction caused by changes in temperature and humidity.
Drying/Curing Time: A 10 mil wet film will dry to touch within 2 hours when temperature is above 65Â°F and humidity is below 70%. Thicker films cure much more slowly. Lower temperatures and/or higher humidity slow the drying process considerably.
The above information is based on research and testing done by Golden Artist Colors, Inc., and is provided as a basis for understanding the potential uses of the products mentioned. Due to the numerous variables in methods, materials and conditions of producing art, Golden Artist Colors, Inc. cannot be sure the product will be right for you. Therefore, we urge product users to test each application to ensure all individual project requirements are met. While we believe the above information is accurate, WE MAKE NO EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, and we shall in no event be liable for any damages (indirect, consequential, or otherwise) that may occur as a result of a product application.