Large tools made the traditional way usually start with large blocks of wrought material that take weeks to procure. Sheet stock used in a laminate tool designed by Fast4m, on the other hand, is readily available.

Water lines are another problem. They are usually the last consideration in tool design because other factors, such as ejector locations, are considered more important. So cooling channels are placed wherever they fit, often not in the best locations. In addition, the usually straight-drilled passages rarely bring coolant to hot spots. Straight-line cooling tends to produce laminar flows through the tool that transfer heat less efficiently than turbulent flows.

And lastly, manufacturers impatient with the performance of a traditional mold may just dial down the cooling cycle. But parts that cool unevenly have more internal stress and can warp.