Glazing History

Prior to the 16th century, most “windows” were openings in the building covered with thin sheets of horn, paper, or oiled cloth. Only the buildings deemed most important were glazed, generally with small panes of glass that were held in lead strips.  Prosperity came in with the Tudor dynasty, and wealth was displayed by the larger size of windows and glazing.

The Italian Renaissance brought an influence on window shape, producing windows that were taller than they were wide, and divided into four panes by a mullion and transom.

The 17th century saw the introduction of the sash window and crown glass – molten glass that is blown into a bubble, pierced, and spun into a disk about four feet in diameter.  After cooling, this glass could be cut into panes which had a slightly rippled effect.  The use of crown glass ended the used of glazing with lead in wealthy households.  The sash window held the glass in place and was capable of being raised and lowered, adding the ability to allow fresh air into the home as well as sunlight.

Due to the fact that crown glass was so expensive, the prominent type of window for most of the population was the casement window with leaded glazing.  By the end of the 18th century, window size became more standardized, and glass production techniques evolved to the point that the cost was reduced, allowing for more of the population to add glazing to their homes and buildings.


Egyptian Glass

Man’s first efforts to make glass are unknown, but the Egyptians were the first to use glass in their culture and art. Amulets and solid glass beads were made in Mesopotamia circa 2500 BC, and the Egyptians began making glass 1000 years later.

The first glass vessels appeared during the reign of Tuthmosis I during the New Kingdom. In the Old and Middle Kingdoms, glass jewelry, amulets, and animal figures were created.

Extensive glass manufacturing began during the New Kingdom around 1550 BC, as it is believed that the craft of glass making was first introduced into Egypt by glass makers captured by Thutmose II, who reigned from 1479 BC to 1425 BC. During this period, attempts were made to use glass in more complicated projects, and the methods of core-forming and cold cutting were introduced. .

Core-forming is the technique of forming a vessel by winding or gathering molten glass around a core supported by a rod. After forming, the object is removed from the rod and annealed. After annealing, the core is removed by scraping.

When cold-working glass the material was treated similarly to stone. Blocks of it could be cut and ground to give them desired shape and drilled to create a hollow space. But glass being very brittle and easily shattered, this method was only rarely employed.     Both methods were abandoned after the invention of the glass blowing technique during the Roman Era.

Decorations were added by pinching the hot glass, adding handles or other features to it like strands of differently colored glass which could then be pinched to change simple straight patterns into more intricate ones.

Coloring agents were naturally occurring impurities or metal oxides added on purpose. The much-coveted blue-tinted glass was made by adding cobalt. Yellow was the result of using iron and antimony, turquoise of copper or purple of manganese [3. Clear, almost colorless glass could be made by adding decoloring agents such as manganese oxide, as was done by the Romans.

In ancient Egypt, glass was regarded as an artificial semi-precious stone, and was given to favored subjects by royalty.   The production of glass declined in Egypt after the 21st Dynasty (1096-945 BC).  Although revived during the 26th Dynasty (664-525 BC), it continued on a much-reduced scale. .

Glass Recycling

Glass can be recycled without losing quality.  Glass is not the only product made from recycling glass, as glass tiles and countertops can be crafted from recycled glass.

New glass is made due to demand, as much “old” or “used” glass is never collected for recycling.

Laminated Glass

Two layers of glass used as bread slices over an interlayer  denotes laminated glass.  Laminated glass is viewed by many as a safer product than normal glass due to the fact that if it is broken, the pieces will remain attached to the sticky surface of the interlayer instead of exploding and erupting into many loose pieces.  This type of glass is commonly used in windshields, and as the cockpit windows of aircraft.

Pyrex Glass

Heat resistant to approximately 500 degrees Fahrenheit, Pyrex glass is safe to use in an oven or a microwave.  Originally made from borosilicate glass, Pyrex glass was first marketed in 1915 by Corning Incorporated, which first used this type of glass in 1912 for railroad signal lanterns.  The glass was adapted to create a baking tray for use in ovens in 1915.

Today, Pyrex glass is made from borosilicate glass and soda lime glass, and is used in applications such as industry, laboratory, and kitchen.

IG Units

Insulated glass is used in projects and homes when a high possibility of heat or cold loss through windows, and energy costs as well as comfort are factors to be considered.  An insulated glass unit is constructed of two panes of glass are put into a metal, or vinyl frame with an air gap between them.  The air gap is usually between 1/2″ to 3/4″ thick.  The standard size for optimum efficiency is 5/8″ thick.  Instead of air, Argon gas can be used as a filler in this space.

This type of window is known in the industry as an IG Unit, or a double-glazed window, and has become the new standard in residential homes as a way to reduce energy costs.

Has your energy bill increased? Think about replacing your windows!

The efficiency and overall condition of windows can deteriorate over time, and may be in need of replacement.  New processes with window manufacturing have lead to increased light performance and with outside cold or heat reduction.  And there are an abundance of styles to choose from to enhance the look of your home.

Contact us today for a free quote!