When calculating sections, you can section through as many models as you wish, in addition to the current model. Obviously, if you section too many, then plotting may become an issue. Whichever of the Calculate options that you choose, you will be asked to define the parameters of the section using a property sheet. One of the pages in this property sheet will be called Models and it is in this page that you define the additional models that you wish to section through.
The Available list shows those models that are available and the Selected list shows those that you have chosen. The current model is always selected at the beginning and cannot be removed. Use the arrow buttons to move the models between the lists. The single arrow buttons will only move the selected models in the appropriate direction whilst the double arrow buttons will move all of the models.
You can change the order of the chosen models using the Up and Down buttons. The order is important in that it is used for the order of annotation when plotting the section. Note that the current model will always remain at the top of the list and cannot be moved.
The Associate Selected check box allows you to associate the chosen models with the current model. This means that the next time you create a section using the current model, the associated models will automatically be selected.
The Defaults button to the bottom left of the property sheet allows you to change the current defaults for plotting sections. For instance, you may wish to change the colour of calculated profiles so that they use the colour assigned to the triangles of a model.