Practice question · Multiple choice
Plaster moulding requires careful mechanical preparation rather than relying on chemical separation alone. Why must a warning layer be tinted and placed immediately against the positive in a waste mould?
Hints
- What makes a waste mould fundamentally different from a reusable piece mould when retrieving the positive?
- Why would a sculptor need a visible cue while mechanically removing the outer casing?
Show the answer
A. It alerts the caster to stop chipping before hitting the cast
Why
Waste moulds are destroyed to retrieve the single cast inside; without a coloured barrier, tools easily gouge the positive. Chemical release and venting resolve adhesion and trapped air, but only visual contrast prevents mechanical damage during breakout.
Practise Moulds II: Materials and Procedure
The app has 5 more questions on this lesson, and keeps your place in the course. Sculpture I is free to start.
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