Glossary - G
Gable
The triangular upper part of an external wall formed by the sloping ends of the roof.
Galvanised iron
Steel or iron that has been zinc-coated generally by immersion in a bath of molten zinc.
Gelling
A condition in which a paint changes usually on storage into a -like state and cannot be restored to a usable condition.
Gesso
A composition for executing designs in relief on woodwork and plaster - made of whiting and glue or plaster of Paris and size.
Glaze
In painting this refers to a transparent or lightly pigmented coating used to modify the previously applied coating to produce a rich effect in depth.
Glazing
When used as a painting term denotes the application of a thin translucent coloured coating to produce an effect or depth of colour not obtainable by the use of a fully pigmented paint.
Glazing bar
The shaped and rebated narrow member of metal or wood into which glass is bedded or fixed.
Gloss
The extent to which a painted surface reflects light. The degree of gloss may be described as ranging from: matt or flat (having no visible gloss); eggshell; semi-gloss; full gloss (usually meaning the highest obtainable gloss).
Gold size
A general description for an adhesive used for affixing gold leaf. It can be either a gelatine or glue-size or an oil-varnish. The latter product is now usually meant and is also used as a drier in oil paints or a hardener/drier for stopping and filling compounds. It should more correctly be termed 'Japan gold size'.
Gold-leaf
Pure gold beaten out to produce an extremely thin leaf (approx. 1/2000 000 of an inch) and applied to surfaces to be gilded.
Gouache
A method of painting with opaque colours that have been ground in water and mixed with a preparation of gum; also any picture painted by this method.
Graining
A method of imitating the grain of wood by the application of semi-transparent coat or coats over a painted groundwork. It should not be confused with 'staining' which is the direct application of a coloured stain or coating direct to bare timber.
Grinning
When a paint does not completely obliterate the under-surface the latter is said to be 'grinning through'.
Ground
A general term for a surface suitable for painting; also used for an undercoat particularly an undercoat for graining or glazing.
Grout
Thin fluid mortar or cement mixture for filling joints or interstices or for bonding loose rubble.
Gypsum
A hydrous crystalline calcium sulphate used as an extender pigment in some paints and in special cement paints and is the basis of some wall plasters.
Graffiti
Graffiti is a very difficult problem to deal with and may require a specialist removal company in the most severe cases. Normal decorative paints are not suitable for painting over graffiti as many felt marker inks and aerosol spray paints tend to bleed through conventional coatings. Take great care when attempting to remove graffiti from unpainted surfaces, especially when the substrate is porous. To avoid permanent damage to the affected area it may be best to seek professional advice.