Sizes and Grounds
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
paintingno matter how beautifulto 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
- 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.
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
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.
PVA Size is available in the following sizes: 8 fl oz, 32 fl oz.
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
Gamblin Ground is available in the following sizes: 8 fl oz, 16 fl oz, 32 fl oz.