How do I build a mold box and what materials should I use to build it?

Article courtesy of Smooth-On, Inc.

The purpose of a mold box is to contain the liquid rubber (after it is poured over and around a model) until the liquid turns to a solid. A mold box does not have to be a complex structure; depending on the size and configuration of your model, often a coffee can, cake pan, plastic bucket or paper cup will suffice. Some mold makers will use cardboard or foam core to construct single-use mold boxes.

If you make molds of flat, two dimensional models on a regular basis, there are a number of advantages in constructing an adjustable mold box. The video below demonstrates how you can use acrylic or wood board to construct an adjustable, reusable mold box.


This FAQ article is offered as a guideline and offers possible solutions to problems encountered during mold making and casting. No warranty is implied and it is up to the end user to determine suitability for any specific application. Always refer to the provided Technical Bulletins (TB) & Safety Data Sheets (SDS) before using any material. A small scale test is suggested to determine suitability of any recommendation before trying on a larger scale for any application.