High Dies with Build Ups are traditionally used in the thermoforming plastics industry. These types of dies are used to cut thermoformed plastics with heights that exceed traditional rule sizes. The steel rule, which is bent by machine, is secured to the wood using bolts instead of being bridged in. This opens up the interior of the die so you can start cutting the thermoformed pieces without damaging the blister.
An aluminum backing plate is cut to match the die-board and then the build ups (made from wood) are added giving the desired clearance height. The reason for the aluminum is so that the steel rule does not get driven into the wood and ensures a flat cut. Heights are fully customizable so if you are cutting multiple pieces at different specs, the dies could all be built to the same height allowing you to cut multiple different pieces at once.
