Two-dimensional/3-D mold design is probably the most popular way of designing a mold today – you can have control over the appearance of the flat 2-D design, the speed of the initial layout, and the precise geometry and functionality of the 3-D solid model.
Many customers today provide a 3-D solid model to the mold shop.

This model can be imported into any of the software packages that are being used today. The mold designer imports the model, reviews it against the part drawing and checks the features that need to be addressed for molding (and moldmaking). Once the material shrinkage has been added, he is ready to use the geometry for the mold design.
When using this option for mold design, there are two approaches that can be used:

1. The designer takes the model, creates slices or cuts through it and then takes that geometry into the 2-D realm and completes the cavity/core layout for the design and detailing. This approach typically is used when the mold designer is using two different CAD packages for mold design and detailing. This way the designer does not have to use the product drawing to create the views that are needed – this is a large timesaver for the designer and the mold shop. The designer also could create the cavity/core assembly as a 3-D assembly, then create the section cuts and bring it into the 2-D drawing space.

2. Complete all of the cavity/core detailing work in 3-D. Then use the section cuts and place them into the 2-D mold design as mentioned above. The advantage is that the cavity/core detailing remains parametric. This is the most important part of the mold design, so it is best used this way. If different software is used, there could be a visual difference in the hard drawing copies, but in time this difference is easy to get used to when you consider the savings and advantages.

When using this approach, we need to remember that the 2-D mold design is not parametric to the 3-D detailing. So if a change is made to the cavity/core area, it will need to be changed manually in the 2-D drawing space. There are ways to make this more user-friendly through the 2-D CAD program for advanced users, but the geometry will need to be manually manipulated somewhere along the line.

Companies or designers will take this course because they usually use two different software packages for their 2-D and 3-D work. Many designers started off designing on the drafting board or using 2-D software, with which they became well versed in using; however, as the investment into 3-D increases, a new software package that is strong in solid modeling is typically used, which usually does not have a strong 2-D interface or the appearance that is desired by the designer or customer.