Traditionally, leadlight windows differ from stained glass windows principally in being less complex in design and employing simpler techniques of manufacture. Stained glass windows, such as those commonly found in churches, usually include design components that have been painted onto the glass and fired in a kiln before assembly. The extra time and cost employed in painting and firing the glass usually prohibited its use in domestic architecture. While stained glass windows are found principally in churches and ornate buildings, leadlight windows, which rarely employ painted components, are much more common, and from the 1860s to the 1930s were a regular architectural feature in many private houses and cottages, where their style is often a clue to the age of the building.
Unlike stained glass windows which are traditionally pictorial or of elaborate design, traditional leadlight windows are generally non-pictorial, containing geometric designs and formalised plant motifs. Leadlight windows almost always employ the use of quarries, pieces of glass cut into regular geometric shapes, sometimes square, rectangular or circular but most frequently diamond-shaped, creating a "diaper" pattern.
A further difference between traditional stained glass and leadlight is that the former almost always has painted pictorial details over much of the glass, requiring separate firing after painting by the artist. In traditional leadlight this is not the case, painted quarries being separately produced and leaded in with those of plain glass, in the form of armorial crests and occasionally small scenes painted in grisaille (grey). Quarries painted in grisaille were employed both in the Medieval period and in the 19th century, the most famous ancient windows to have been decorated in this manner being in York Minster; these have inspired many 19th century imitations painted with little birds.
Quarries may be mould-cast into patterns such as fleur de lys and imprinted with black and yellow stain. Used extensively during the 19th century in England and Commonwealth countries, these quarries are often the product of a single studio, James Powell and Sons of Whitefriars. Another form of decorative quarry is the etched or engraved quarry, which is made of flashed glass, most often ruby red or royal blue over a transparent layer. It then has a design cut into it using either acid or a lathe, the character of the resultant design differing accordingly. Etched quarries of Venetian glass are often employed, sometimes in conjunction with panels of stained glass, particularly in Italy and Eastern Europe. Lathe-cut quarries with a simple star-burst pattern are very common in the late 19th century domestic architecture of many regions, both in leadlighting and in simpler wooden-framed glazing.
The colours employed in leadlight windows may range from delicate pastels to intense hues. The glass used may be textured or patterned or bevelled. However, since they are generally non-pictorial, and are primarily to illuminate the interior, with or without a decorative function, the glass is usually of pale hue, or transparent.