PCB-Investigator offers many mouse tools. Those, familiar with Microsoft Windows, most likely already know, like panning and zooming. Even though you can also select those functions via "Start » Mouse Tools", it is arguably faster to use your mouse: holding down the right mouse button to pan, scrolling the mouse wheel to zoom and clicking the left button to select. So, you can use all three of the most needed functions without having to switch manually via the menu each time. But there are also those mouse tools you will need to select via the menu depending on the situation for example "Select in Rectangle". The crucial difference between the simple "Select" and "Select in Rectangle" not only is in the selecting method (clicking vs. drawing a rectangle around the area you want to select), but also in the amount of components you can select with one action. "Select" will get you the smallest component beneath the point you clicked as well as directly tangent parts (each further click on the same point will toggle through all components of all activated layers beneath that clicked point in order of size from smallest to largest), whereas "Select in Rectangle" will get you every component on every activated layer contained in the rectangle and their tangent parts. If you want to select more than one object, you can do this by holding down the shift key and selecting the additional objects. Please note that a click elsewhere without having shift pressed will result in a deselection of all selected objects, to deselect a specific object keep "ctrl" pressed and select the object you want to deselect.

Another possibility for comfortable and quick deselection as well as many other useful use cases are mouse gestures. Mouse gestures are predefined paths you have to "redraw" with your mouse while pressing down your mouse wheel to trigger the associated function. You can activate or deactivate Mouse Gestures via "Help » Strokes on/off".

The following mouse gestures are currently available in PCB-Investigator:

Zoom Strokes
	View Area (zooms in on the area the stroke was excecuted over; stroke length is vital; in contrast to "Zoom In" no pre-defined zoom steps)
	Zoom Home
	Zoom In
	Zoom Out
Dialog Strokes
	Help Strokes (calls up an overview over all available mouse gestures)
Other Strokes
	Selection Buffer
	Attribute Histogram
	Measure Dialog
	Select Mode on/off
	Object Attributes
	Toggle Drawmode
	Clear Selection
	Show Oversize

The default mode is the most primitive net selection mode, it selects a net and all its related components based on the net names given in the data set regardless of the layer they are on. Please note that there are data types for example Gerber that do not contain net information and thus cannot use the default net selection. Please also be aware that the default net selection does not change the current view meaning, e.g. it doesn't change the current layer even if the majority of the net is on a different layer.

The Crossover mode serves the purpose of signal tracing. Though logically one net, nets often are divided schematically at a resistor. The crossover mode skips these small blocks like resistors to link logically close related nets again to show them in their entirety. Since it is not beneficial to skip too many components - because the nets would get too large and therefore make the view become meaningless -, there is a pre-defined limit of how many components are skipped. It can be adjusted under "Start » Options » Net Selection".

The Current Layer mode is very similar to the default mode, in contrast to the default mode however, the view of the Current Layer mode is - as the name implies - entirely limited to the current layer.

The Best View mode is used to monitor network routes over several layers. It achieves this by combining four steps:

1. Selection like the default mode
2. Activating all concerned layers (visualisation in accordance to the respective layer colours)
3. Zoom to Selection (make the complete selection visible in the viewing area)
4. Activate "draw only selected" option (everything else gets faded out or made transparent)

The Shape mode calculates all touching parts of one layer and selects them. Since this is achieved independent of the net name, it also works for Gerber and other formats that do not contain net information.

A common use case for the Shape mode are nets that physically are one but have - because of administrative reasons, e.g. because otherwise they would be too large - been divided into two or more nets with their own net names in the schematics. These nets are marked as logically linked through so-called star points which indicate a fully intentional short curcuiting. With the default mode you would only be able to select the divided parts separately while the Shape mode provides you the whole coherent network.

The Shape through Drills mode is similar to the default Mode, it selects all touching parts across all layers, which are connected through drill holes provided the layer stack up is correctly specified. The later states which drill holes link which copper layer (vertical lines in the layer matrix menu).