Cames Pieces of lead into which the glass edges are placed.
Cathedral Glass Can be clear or coloured but essentially will let light through and you can see through it unless the texture prevents this.
Clear Glass Not necessarily see through as the texture may prevent this but any glass that does not have colour.
Coloured glass Glass that is not clear usually the colour is all the way through the glass (not to be confused with the imperfection of the green tinge of clear float glass). The colour has been created during the glass manufacturing process.
Conservation Protection, management and retention of the original.
Cullet Off cuts of glass. Irregular in shape and size and usually sold by weight and pre packed.
Fenestration Arrangement of windows in a building
Fensa Stands for Fenestration Self-assessment Scheme.  Unless your building is listed you must obtain a certificate of compliance.  Only a Fensa registered installer or the Local Authority Building control can issue these.
Float Glass  A method of producing glass so that it is perfectly flat on both sides. The molten glass is ‘floated’ onto a bed of hot melted tin.
Glass Fusing The action of bending and or melting glass together in a kiln.
Grain Glass sometimes has a perceived grain however this is only colours lying within a piece of glass and there is no real grain to glass.
Laminated Glass  Two pieces of glass stuck together by a plastic interlayer which holds the glass together if it is broken(Like modern car windscreens).
Leaded Glass A window that has the glass held in place with lead cames.
Leaded Light A light is an old traditional name for a window.  Nowadays Leaded Light is generally used to describe a window that uses leads to hold clear glass in various designs with the most common being diamonds or rectangles.
Opal Glass Glass that has a solid colour preventing images being seen through it but allowing light through depending on the density of colour (e.g. black opal glass allows no light through it).
Opal Streaky A combination of Opal and Cathedral glass in the same sheet so elements of the glass are see through and others not.
Painting on Glass Specially prepared paints that are applied to cold glass which is then fired in a kiln to fire the paint into the glass permanently.
RAL A recognised system for conveying a standard colour in a number format (another method is the Pantone system but the UK generally uses the RAL system).
Restoration Re new, repair or re-establish.
Stained Glass A name correctly applied to glass that has been hand painted with various stains and paints which is then fired in a kiln to transform it to a permanent image.
Texture  Various methods are used to create an imperfect surface on one side of the glass this is call the texture. Always one side of the glass will be shiny (the side we cut).
Tinned Coating by the application of a solder containing lead/tin.
Window Guards Guards are used to protect valuable glass.  They are normally either, clear laminated glass, powder coated stainless steel mesh, polycarbonate or isothermic.  There are pros and cons to each method. We carry out a survey to advise on the best options for any particular problem.
Toughened Glass A process that heats the glass and then rapidly cools it.  This creates tension in the glass so that if it accidentally gets broken it shatters into small pieces.