Surface modelers still have two general advantages over solid modelers for the first stage of the mold design, the creation of the core and cavity.

First, they tend to be more tolerant of poor quality data. Both types of programs offer methods for fixing problems—such as poorly trimmed surfaces or overlapping edges—that might result from inexperienced product designers or inaccurate data translation. However, surface modelers can usually import data that a solid modeler might fail to accept at all.

Many surface and solid modeling programs offer wizards that can automate the creation of the core and cavity design from the part geometry. In both cases, the wizards allow the process to be completed more quickly. However, surface modelers are more flexible when the split surface generated by the automated method needs small adjustments to give the optimal design. In general terms, solid modeling can be better for simpler product designs because it remains easier to use, while the greater flexibility of surface modeling will be better for producing tooling from more complex components.

The other key choice for the tooling designer is whether or not to import the design history with the product model. This history shows how the design was created and maintains relationships between different elements of the design. Supporters of an integrated-software approach to product design and mold design claim that this is important as it allows changes to the product design to be reflected automatically in the mold design. However, retaining the history can be a disadvantage when making minor changes to the product design to aid manufacturability.

For example, the mold designer might want to increase the radius of one fillet in the model to improve material flow, but find that this is impossible without altering other linked fillets. Similarly, he may wish to increase the draft angle on a single surface to make it easier to remove the part from the mold and discover that this cannot be done without affecting other surfaces.