# What Is a Counter-Mould in Construction?
**A counter-mould (also called a counter-template) is a negative mould taken from an existing profile, ornament, or shape so that it can be accurately reproduced. It captures the exact inverse of a surface, allowing craftsmen to replicate decorative elements, cornices, or mouldings with precision.**
## How Counter-Moulds Are Made
A counter-mould is created by pressing or casting a flexible or rigid material against the original profile. Common materials include:
– **Zinc or sheet metal** — cut to match a cornice profile, then used as a running template
– **Plaster** — poured over an original to create a negative impression
– **Silicone rubber** — flexible moulds for complex three-dimensional ornaments
– **Polyurethane** — durable moulds for repeated casting
The resulting negative accurately captures every detail of the original surface, including curves, undercuts, and fine decorative textures.
## Applications in Construction
**Restoration work** — when a damaged cornice or ornament must be repaired to match the original, a counter-mould is taken from an intact section and used to cast replacement pieces.
**Running cornices** — a metal counter-mould (profile template) is dragged along a guide to create long plaster cornices with a consistent cross-section.
**Reproduction** — historic decorative elements can be replicated for new buildings that must match a period style.
## Counter-Mould vs. Mould
The counter-mould is the negative (inverse) of the desired shape. When material is cast into or run against the counter-mould, the result is a positive reproduction of the original profile. The terms are sometimes used interchangeably, but strictly, the counter-mould is always the negative template.
## Importance in Heritage Conservation
Counter-moulds allow restorers to reproduce ornamental details that are no longer commercially available, preserving architectural heritage with historical accuracy.
## Related Terms
– Cornice
– Plasterwork
– Profile
– Template
– Restoration
– Casting
Want to learn more about construction terms? Visit our [knowledge base at fredsdiyplans.com](https://fredsdiyplans.com).