What To Look For
Type of Glass
Some form of patterned or textured glass is often more desirable than clear glass. A "bullseye" or dalle is an indication of good age. They were typically made in Holland or Germany and imported to England. As well, in a window with no colour, look for the number of different patterns of opaque glass.
The total number of pieces of glass is important.The number of curved pieces/cuts is important, as simple rectangular pieces make for a plainer window. The more realistic representation of the feature (i.e. a flower) is an indication of an older age, since these shapes became more stylized over the years. Some windows were part of a set and you can see where one part leaves off and another window would have continued.
English lead is typically heavier than antique North American lead. A small bow is an indication of age, window weight and its past placement on a south facing wall. Typically, these bows are not significant. If worrisome, however, the bowing out can be corrected. This can be done by laying the deframed window on a flat surface in the direct sunshine on a warm day. Place a light weight (i.e. a tin of soup) on the peak of the bow and leave it there for several hours, while making sure to place a spacer below the window so that it does not "sink through". This procedure usually works well.
Certain colours are very expensive (i.e. certain types of reds cost over $500 per sq. metre). Some coloured glass is textured or may have ripples/streaks in it. This is typically a higher quality glass.
If the original frame is in good shape, it will finish up well. The wood is usually pine. If some of the putty is missing, it usually isn't a problem unless the window can be shaken in its frame. Some of the re-framing is done with rough wood, while other re-framing material is smooth enough to be refinished as it is. As well. professional reframing, which is seen on many windows in our store, adds to the cost.
The mastery of the artisans in years past is often witnessed eloquently in antique painted windows. The fineness of the stroke, the rendering of a bird's wing, a face, even a crease in a gown - all of these are captured permanently in stained glass. Each colour must be fired separately, using specialized glass paints. The results are usually nothing less than astounding and respect for the long hours put into these windows makes them a true treasure.