With the mouse cursor you can make the chosen cuts of the plotted image. As soon as a trimming box of any size is defined you can use the Trim menu command to start trimming (or use another methods). The trimming starts automatically if the Dynamically Trim item in the Options menu is checked.
The trimming is performed so that the selected trimming box is enlarged to the entire drawing area (note that the size of the screen drawing area can be changed through the Zoom or Resize menu command or automatically with the change of the size of the client area if the Dynamically Resize item in the Options menu is checked).
If the Proportional Aspect Ratio item in the Options menu is checked, you can choose from two trim types: Exact or Proportional to Paper Size. If you choose Proportional to Paper Size trim type then the aspect ratio of the displayed cut is identical to the aspect ratio of the currently selected paper size (see the Paper Size dialog), regardless of the aspect ratio of the selected cut. To ensure such proportional aspect ratio of the displayed cut, the size of the displayed cut area is usually larger than the size of the selected cut area. The selection of the trim type is made either in the trim command menu (if the Dynamically Trim menu item is not checked) or is determined by the Prefer Exact Trim menu item switch (if the Dynamically Trim menu item is checked).
If the Proportional Aspect Ratio item in the Options menu is not checked, the selected cut area is always identical to the displayed cut area (conforms to Exact trim type) and is fitted to the entire drawing area. This usually leads to the deformation of the displayed image.
To expand the picture into the original size you can do the following:
Another purpose of the trimming box (hence selection box) is to select a part of the picture for printing or exporting (see the Print or Export dialog for details) or for copying to clipboard (see the Copy Image to Clipboard command) or to define a window for zooming. Note that the Dynamically Trim menu item must not be checked for that purpose.