This tutorial covers how to add comments, notes, and other modifications to a drawing without changing its original content.
The Redline mode enables to mark up a drawing. But the drawing itself remains unchanged, all modifications are saved in a separate DXF or DWG file. It is a good solution when you need to review designs.
Open your file, click the Mode button in the upper right corner of the ABViewer window and select Redline.
The appeared red frame indicates that the Redline mode is activated and you can start making necessary changes. All the drawing and modifying tools are available. When you are done, go to the Advanced tab, open the Redline drop-down list and select Save Redline.
By default, the Redline file is saved in the Redline folder. Its name consists of the loaded file name and postfix "_dxf$$Model". And next time when you open your drawing, the Redline file will be automatically loaded. If you change the file name and/or its path, you can load the Redline file using the Load Redline command. It is located on the Advanced tab in the Redline group. There you can also find the Hide/Show Redline command.
To exit the Redline mode, click the Mode button in the upper right corner of the ABViewer window and select Editor or Viewer.
If you want to change the Redline mode settings, go to File → Options → Editors.
Speaking about the Redline mode, we should also mention the special Markup mode that is activated on the Editors tab.
If this mode is activated, you cannot edit or delete the entities of the opened file. It is possible only to create the new ones. These new entities are automatically placed on a layer named "markup" and saved in the original drawing, i.e. a separate file is not created as it is in the Redline mode.