Tracery is the ornamental and structural stone framework in the head of a Gothic window. It divides the large arched opening into smaller lights, so that the leaded glazing stays at a workable size and so that wind load and self weight are carried down into the jambs. The Dutch term maaswerk refers to the meshes — the openings — formed between the stone bars.
Development
- Plate tracery — the earliest form: openings are pierced through a solid stone plate. Stone dominates over glass
- Bar tracery — from the high Gothic onwards the openings grow so large that only slender moulded stone bars remain. The window becomes far lighter and more open
- Flowing or flamboyant tracery — in the late Gothic the lines curve into flame like, S shaped forms; the mouchette or fish bladder is the defining motif
Common figures
- Trefoil — three joined arcs of a circle
- Quatrefoil — the same figure with four lobes
- Mouchette — an asymmetrical, teardrop shaped figure of the late Gothic
- Rose window — a large circular window whose whole face is filled with tracery
In structural terms
Tracery is not applied decoration; it is load bearing stonework. The bars are built up from separate, precisely worked blocks with concealed joints. Those joints are exactly where restoration problems appear:
- Weathering. Rainwater stands on horizontal surfaces; freeze thaw cycles then delaminate the stone
- Corroding cramps. Old iron cramps, dowels and saddle bars expand as they rust and split the stone. Replacing them with stainless steel is standard restoration practice
- Replacement. Decayed tracery is replaced piece by piece — same stone type, same tooling, and as little original material lost as possible
- Glazing. The leaded lights sit in a rebate in the tracery, bedded in putty and supported by saddle bars
Related terms
- Gothic
- Arch head
- Trefoil
- Leaded glazing
- Natural stone
- Flamboyant style
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