Hirst Arts makes a variety of silicon rubber molds for casting building blocks for constructing fantasy buildings and structures.
From the Hirst Arts website:
ABOUT HIRST ARTS
Hirst Arts is a small business owned and operated by Bruce and Joanne Hirst. We make all of the molds by hand and ensure that each is of the highest quality. Each order receives our personal attention and usually ships out the day after we receive it.
Our Mission Statement
To create molds that can be used for customers to express their architectural dreams and make those structures come to life.
To make molds and kits simple enough that most people can understand how to use them in creating models.
To supply easy-to-follow instructions that are clear and allow a person to picture themselves successfully using the molds.
To ship the molds in a timely manner and ensure customer satisfaction with every product.
To increase my own skill as a modeler and express my architectural visions through each new mold and project. -Bruce Hirst