How does Background, Foreground and Normal Plotting Work?

In Trimble Business Center there are two sets of hierarchy’s that get used to determine what plots on top of what on a drawing output to Plotter or PDF. The hierarchy’s are as follows

Object Type Hierarchy
The object order from Back to Front Plot Order cannot be user controlled, it is hard coded and works as follows

Background Images and PDF Pages, Fills and Hatch Patterns
Linework, Points, Symbols and Blocks
Text objects

Layer Hierarchy
In the Layer Manager you can specify 3 levels of plot / print order, and these control the order in which the same types of objects will interact with each other on a plot sheet. The Object Type hierarchy is applied first and then the Layer based hierarchy second

Background
Foreground
Normal

While user logic might say that Normal goes between Background and Foreground, Normal is always assumed to be the highest order and is the default. The other two settings push the object priority back 1 or back 2 slots from Normal.

Color Hierarchy
In the help system it states that if two objects of the same type are on the same layer and therefore have the same plot priority then color is the last decider. It states that the color list sequence determines what goes where in the color hierarchy. I personally am not convinced or clear on how that works because in tests the list of standard colors did not prioritize top to bottom or bottom to top as far as I could tell. If there is a color hierarchy, I am also not sure what happens when you mix in Custom Colors. I am trying to get to the bottom of this part of the solution and will report back when we have a good answer.

Anecdotal Information

  1. There is also some user feedback that would indicate that True Type Fonts take a higher priority than normal stroked fonts when it comes to Text objects. What I see is that when TBC writes a PDF from a project where there are True Type Fonts, the True Type Text is written like Filled Polygons, and those seem to clash with the Linework and do not appear to sit nicely on top of the linework and fills. If you use Stroke Fonts they appear to plot much better in general when using PDF output. This may of course depend somewhat on the Print Drivers in use.

Example of True Type Text output

Example of Stroke Type Text Output

  1. I am looking into what happens with lineweight if anything in terms of changes in priority.