The Ground is the foundation of an oil painting. Artists for whom building permanent paintings is important should consider carefully the quality of all layers of their paintings. They should be as concerned about the layers they do not see (size and ground) as the layers they do see (oil layers, painting mediums, and varnish). A basement made from poor quality concrete will bring a house down and an inferior ground will cause the painting—no matter how beautiful—to fall apart.
SIZES for Oil Grounds – A size seals the porous fabric and isolates it from the ground and/or oil paints. Linen and cotton will prematurely rot without a size layer. Only fabric supports need sizing. Panels only need to have a ground. Acrylic gesso does not require a size.
Traditionally, gesso was not applied to fabric supports, only to panels. The name “Gesso” was inappropriately given to acrylic grounds during the 1950’s, causing confusion among painters still. So as not to increase the confusion, Gamblin Artists Colors Co. uses the traditional terminology.
For oil painting, “ground” is applied to sized linen or canvas.
For oil painting, “gesso” is applied to panels
Gamblin Oil Painting Ground makes a strong, bright, non-absorbent foundation for oil paintings. Gamblin Ground is formulated from alkyd resin, titanium dioxide, and calcium carbonate – titanium dioxide gives opacity, while calcium carbonate gives tooth for strong adhesion.
Gamblin Ground makes a brighter and less-absorbent ground layer compared to acrylic “gesso” – meaning that oil paint layers on top will better retain their color saturation. In addition, the lower absorbency allows for “reductive” underpainting techniques when painters need to wipe back to the white of the Ground.
Gamblin Ground can be tinted with our FastMatte Alkyd Oil Colors when creating a colored ground.
Because the percentage of pigments is so much higher than in acrylic “gesso”, painters need only apply TWO coats of Gamblin Ground instead of the recommended four coats of acrylic. Fabric supports should be sized with PVA Size before applying Gamblin Ground. Also, Gamblin Ground can be applied on top of acrylic gesso for a brighter white, less-absorbent ground layer.
Gamblin Ground is thicker than acrylic gesso, and requires different application techniques, which are demonstrated on our Video Demos page.
Gamblin Ground is available in the following sizes: 8 fl oz, 16 fl oz, 32 fl oz.
Rabbit Skin Glue (RSG)
This is the traditional size for fabric support. Conservation scientists caution painters that rabbit skin glue absorbs atmospheric moisture on damp days and swells, gives off moisture on dry days and shrinks. This movement of the size layer can cause aged oil paintings to crack according to the Smithsonian Conservation Lab.
Rabbit Skin Glue (RSG) is available in the following size: 1 lb.
Gamblin Gesso makes a traditional absorbent ground for oil paintings on panels. “Gesso” is Italian for gypsum which, when mixed with water and animal glue, makes a luminous painting surface. Gamblin Traditional Gesso is a dry mixture of rabbit skin glue, gypsum, marble dust, and titanium dioxide. Robert Gamblin recommends applying four coats Traditional Gesso to both sides of thin or poorly braced panels. Traditional Gesso is too brittle to use with fabric supports.
Traditional Gesso is available in the following size: 1 lb (3 applications).
Diluted with distilled water, PVA size is a contemporary size for fabric support. Conservation scientists recommend painters use neutral pH PVA size on linen and canvas instead of rabbit skin glue. PVA provides a good size layer that seals the fabric but does not re-absorb atmospheric moisture, swell and shrink like rabbit skin glue does. There are hundreds of different formulae of PVA. We acknowledge and appreciate the research of the Canadian Conservation Institute that helps painters and conservators identify the best PVA to use. Gamblin PVA Size is made from PVA that has a neutral pH and does not yellow. It also retains its flexibility and does not emit harmful volatiles.
PVA Size is available in the following sizes: 8.5 fl oz, 33.8 fl oz.