Tracing the Line

In most media, a line is an insubstantial thing; no more than a trail of paint, graphite, or charcoal across a paper or canvas surface. Lacking weight and dimension, the line leads a precarious existence. At any moment, its bold journey across the surface may be obliterated by the friction of the eraser, the smudge of a careless hand, or the obscuring coat of paint.

Contrast this with the lead line in stained glass. Now here is a line with substance; with weight and presence - and one with a long and noble history.

Throughout the thousand-year history of stained glass, the lead line has played a crucial role. It was born of necessity, somewhere around the 11th Century, as a way to create larger windows with the small pieces of glass that were all that could be made at the time. Its precursors were the stucco, wood and chiseled stone matrices which formed the framework for the intricate pattern windows of the Middle East.

Lead came consists of strips of lead which have been extruded with an H-shaped cross-section, to provide twin channels for the glass to rest in. These are placed between the glass pieces, soldered at the joints, and the channels packed with a putty compound to hold the glass firmly in place. The advantage of lead over other materials was its flexibility, sturdiness and stability in the colder Northern climates, where winter ice, water and cold made the use of open, stucco-based methods less practical [footnote: The term “lead line” is used here as a generic term for a double-channel structural material for constructing stained glass windows; recognizing that other materials (e.g. zinc) are also used in place of lead came.].

Although the invention of lead came solved some problems for the designer, stained glass as a medium continued to present challenges. Unlike a drawn line, which can be lightened or darkened, a lead line is uncompromising; it stops all of the light along its path, with no middle ground or fine gradations. In addition, designers had to work with the limited sizes of available glass, and the inherent structural requirements of a stained glass window. However, the challenges of working within these constraints were more than balanced by the sublime beauty that could be achieved when fine glass was suffused with sunlight. Inspired by the possibilities, generations of designers were able to create and advance a beautiful artistic style, which was distinctive to stained glass.

Artistically, lead lines are used in a number of ways. The oldest of these is to create a visual pattern that shapes and arranges the glass for decorative effect. In windows with imagery, lead lines can be used to frame the individual artistic elements. Alternatively, they can take more of a background role. Arranged in a gridwork or a regular pattern behind the images, with paint or silver stain providing the detail, lead lines can provide an intricate counterpoint to the main design of the windows.

Although it started out as a structural element, lead came, and the continuous lead lines it presents to the viewer, became one of the defining characteristics of stained glass windows. (Even today, a pattern of lines intertwined across a window shape are widely recognized as depicting stained glass.)

For many centuries, the lead line was an inextricable part of the stained glass. Then, in the Renaissance, there began a marked decline in the use of lead in windows. This was largely due to two factors: First, technological developments allowed the manufacture of much larger sheets of glass, and it became possible to build a window from large, undivided glass rectangles. Secondly, the artistic tastes of the Renaissance favored lighter, more naturalistic, painted windows. Of course it was much easier to achieve a sense of “lightness” if one could eliminate the visual intrusion of 1/4" wide strips of lead between each piece of glass. Likewise, the naturalistic look was much more convincing when the carefully painted face wasn’t surrounded by a line of lead. It was only a matter of time before stained glass windows began to lose their intricate lead lines, in favor of painted enamels within geometric shapes, joined by a metal framework along the edge.

With the Gothic revival of the mid 19th century, the lead line again came into its own, as artists tried to emulate the dramatic structure and visual power of the Medieval windows. Hand-made colored glass was re-invented and enamel painting in windows fell into disfavor. Both the Gothic windows, and the Victorian style windows that followed them employed both structural lead lines and “drawn” lead lines; the latter achieved with the use of paint.

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Over the past century, there has been a distinct divergence among artists in their approach to the lead line. Freed from some of the technical constraints of the past and excited by the possibilities of a more open style of stained glass, a number of artists began to work in this direction. An important development in this area was the invention of the copper foil technique by Louis Comfort Tiffany. This technique uses thin strips of copper, which are wrapped around the edges of the glass and then soldered together. Copper foil allows a much more delicate and organic type of line; however, it is also a line that is diminished in size and importance, becoming more like a “seam” than a solid structural element.

In recent decades, even this seam disappeared in some windows, as new adhesives were applied to the development of the applique technique (colored glass glued onto a base clear glass). Dalle-de-verre, in which glass is embedded in concrete, provided another alternative to lead lines.

Even as some artists were exploring the freedom of new, unleaded techniques, others were taking another look at the lead line - not so much as a structural essential, but as a powerful graphic element. This approach was most evident in Germany, where artists took a strong graphic approach - bringing the design down to the bare bones of the lead line. However even these artists could be said to be enjoying the freedom allowed by newer techniques and materials, as they play against the viewer’s expectations with lead lines that dead-end, splay, and even leave the surface of the glass.

Over the past decade a broad range of techniques is being used - some with lead lines and some without. Most people are familiar with the traditional leaded windows; but it is interesting to see what is happening “beyond the line.”

Marc Chagall’s windows created in the 1960's (figure 1) utilize leads as a counterpoint to the composition - the leads are not overly important to the window design. This works well when the color of the window is monotone.

Brian Clarke’s windows, although highly graphic, are based on a similar principle, in that the color field composition/painting transcends the lead lines (figure 2). In these windows, his structural grid of lead lines is not intended to disappear altogether but to strike a balance between a graphic statement and a color composition - while giving equal weight to both of these. The use of opaque glass is helpful in achieving this effect.

The windows of Georg Bernhard are an example of a completely painterly approach. Fired on a single sheet of antique opal glass, the windows combine glass paint and silver stain which have been applied not with brushes, but with a specially fashioned paint-stick, so that he could draw directly on the glass.

Jürgen Reipka’s window is created from full sheets of flashed blue glass, which become the canvas of a painter. Energetic splashes and slashes of paint cover the glass. Bold silver staining and sandblasted white glass are not decorative “effects,” but integral to a painterly composition.

Graham Jones’s window moves well away from line. In this piece, a sandblasted screen provides the background, in front of which the colored glass is fixed in a sculptural metal framework. Both surfaces are separate fields of light, color and texture.

Beate Wasserman’s work is an example of the use of the very high-tech adhesives that are available today. In this project, the glass is joined directly, edge to edge, with no dark joining line. The effect is of a color field painting, but done in luminous glass.

Lead lines have many positive qualities for the artist: structurally, they allow the artist to change color and texture across a window. They are also strong graphic elements in and of themselves. With them, the artist can outline, accent, and give visual complexity to areas of a window. Lead lines have a boldness, power and depth that is unequaled by any other stained glass technique. In using lead lines, artists have to understand and respect their power. The visual interest they provide, can easily be overdone, so that they end up dominating the window. The window becomes something that is “about lines”, rather than “about glass.” At the other end of the spectrum, the complete elimination of lead lines must also be approached with care; otherwise the work may become too light and insubstantial.

There is beauty and excitement in both the oldest and the newest techniques for creating stained glass. Whatever path the artist chooses, he or she ought to stop occasionally, and thank those who have gone before. The lines they created continue to weave through the history of stained glass. They will never be undone.