TORONTO - Tools, training and talent aside, the one thing you really need to make a piece of stained glass is time.

“A stained glass window, if it is truly a stained glass piece, you put in about five months,” said Joseph Aigner, owner of Artistic Glass since it opened in 1971. “That’s realistic. If it is just coloured glass and leading, that’s different.”

For a piece to be genuine stained glass one must paint it, heat it in a kiln to 677 degrees Celsius, and repeat as necessary. Each time this is done, four times on average to produce a detailed face, it takes about 16 hours because once the glass is heated it requires half a day to cool before a second coat of paint can be applied.

Not only is this the defining characteristic of stained glass, it is also a very time-consuming stage of the process — one which many people never associate with the semi-transparent art work.

“A lot of people have the imagination that this is what stained glass is,” said Aigner, pointing to large piece of coloured glass that had been tinted during the manufacturing of the solid glass sheet. “You have to then inform them that what they have is coloured glass leaded together.”

Aside from the paint and bake component, the process of making a piece of artistically leaded glass — be it clear, stained, coloured or more commonly a combination — is the same.

A design is composed and once it satisfies the collective vision of those involved, a full-scale version is drawn up. One of these drawings is then taken and, using wide-blade scissors to compensate for the necessary gaps for leading, cut into the individual sections. These patterns, labelled for further reference, are used to cut out each piece of glass by hand.

Leading is when the multiple sections of glass are bound together. To do this a full-scale pattern is laid out on a table which has one corner fitted with a molding boarder. The molding, which sits higher than the table’s surface, provides the artist with a ridged edge to pin the glass pieces against as stripes of lead are used to frame each.

Once the entire project is laid out and leaded, including the outer edge, all joints are soldered together and then sealed with a specially mixed glue.

How long this all takes varies as much as the number of combinations you can make.

“(It) depends on how many pieces are in it, how difficult it is,” said Aigner, who picked up the craft as a child while working at his family’s glass shop in Germany. “When we make a church project it can take sometimes up to two years to complete.”

There are two major reasons why stained glass windows for churches take so long, said Aigner. First, priests want real stained glass, although most accept a mixture of coloured and stained to keep costs down. The second reason, church projects are large, complex and often multi-window assignments intended to please hundreds of parishioners meaning the design phase is rarely a first-draft success.

“The most challenging thing is to get the design approved,” said Aigner, who is four months into an eight-window project, each representing one of the Beatitudes, for St. Augustine Catholic High School in Markham, Ont. “We had a little bit of a problem finding images for the Beatitudes. I had a little trouble getting a concept ... but now we have a beautiful design.”