In pattern making and general workshop practice, which timber is most commonly chosen for wooden moulds? (Add context: consider dimensional stability, workability, and resistance to wear during repeated use.)

Introduction:
Wooden moulds/patterns in foundry and workshop contexts must balance stability, machinability, and durability. This question probes recognition of a timber that consistently meets these demands in instructional and field practice.

Given Data / Assumptions:

• Patterns experience abrasion and humidity cycles.
• Dimensional accuracy is important for repeat castings or formwork.
• Cost and availability matter but are secondary to stability and durability.

Concept / Approach:
Teak contains natural oils and silica, giving excellent dimensional stability, resistance to moisture changes, and a good finish when machined. These properties reduce warping and extend service life compared with many local hardwoods or softwoods.

Step-by-Step Solution:

Verification / Alternative check:
Teaching manuals and foundry texts routinely cite teak and mahogany as benchmark pattern woods due to balanced workability and dimensional stability.

Why Other Options Are Wrong:

• Plywood: adequate for temporary forms, but exposed plies and glue lines wear quickly.
• Sheesham: hard and durable but tends to move with moisture; heavier to shape.
• Deodar: lighter and easy to work, but less durable compared to teak.
• Generic hardwood: unspecified properties; not a dependable choice for precision.

Common Pitfalls:
Choosing solely on cost or availability; ignoring movement across grain; neglecting surface sealing which all woods (including teak) still require for longevity.

Final Answer:
Teak wood (Tectona grandis)