[[Image:PMOM11.png|thumb|250px|EM.Picasso's Navigation Tree.]]
[[Image:PMOM8(1).png|thumb|600px|EM.Picasso's Layer Stack-up Settings dialog with the initial default values.]]
[[Image:PMOM12.png|thumb|600px|EM.Picasso's Layer Stack-up Settings dialog showing a multilayer substrate configuration.]]
In EM.Picasso, the background structure is usually a layered planar structure that consists of one or more laterally infinite material layers always stacked along the Z-axis. In other words, the dimensions of the layers are infinite along the X and Y axes. Metallic traces are placed at the boundaries between the substrate or superstrate layers. These are modeled by perfect electric conductor (PEC) traces or conductive sheet traces of finite thickness and finite conductivity. Some layers might be separated by infinite perfectly conducting ground planes. The two sides of a ground plane can be electromagnetically coupled through one or more slots (apertures). Such slots are modeled by magnetic surface currents. Furthermore, the metallic traces can be interconnected or connected to ground planes using embedded objects. Such objects can be used to model circuit vias, plated-through holes or dielectric inserts. These are modeled as volume polarization currents.
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<td> [[Image:PMOM8(1).png|thumb|550px|EM.Picasso's Layer Stack-up Settings dialog with the initial default values.]] </td><td> [[Image:PMOM12.png|thumb|550px|EM.Picasso's Layer Stack-up Settings dialog showing a multilayer substrate configuration.]] </td></tr>
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