The Ground is the foundation of an oil painting. Should a builder put up a house without considering the foundation? Should an artist make an oil painting without considering the foundation? It depends on the intention of the artist/builder. 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

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.
MSDS

Rabbit Skin Glue (RSG) is available in the following size: 1 lb.


GAMBLIN TRADITIONAL GESSO
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.
MSDS

Traditional Gesso is available in the following size: 1 lb (3 applications).


POLY VINYL ACETATE (PVA) SIZE
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.
MSDS

PVA Size is available in the following sizes: 8 fl oz, 32 fl oz.


GAMBLIN GROUND
Gamblin Oil Painting Ground makes a strong, bright, non-absorbent foundation for oil paintings. Formulated from alkyd resin, titanium dioxide, and barium sulfate, Gamblin Ground makes canvas and linen stiffer than acrylic "gesso" and more flexible than traditional oil primers. Barium sulfate gives Gamblin Ground its tooth. Titanium dioxide gives Gamblin Ground its opacity.

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. More coats can be added for smoother painting surfaces. Because alkyd resin is used instead of linseed oil as the binder, Gamblin Ground is more flexible and dries more quickly than lead/linseed oil grounds. Lead/linseed oil grounds must dry for six months and Gamblin Ground is ready for paint application within a week.

For more information on our Ground, including application tips, please visit http://www.gamblincolors.com/oil.painting.techniques/grounds.html

MSDS

Gamblin Ground is available in the following sizes: 8 fl oz, 16 fl oz, 32 fl oz.