The undocumented command Tspaceinvaders finds text and mtext that is being blocked by other entities. To run the command, type Tspaceinvaders at the command line. AutoCAD will ask you to select objects. When you’re done selecting, press Enter. AutoCAD reports the number of text objects found that overlap objects. You can choose to step through each text object to verify the overlap. The end result is a selection set of all text objects with overlap issues.

Caption: Tspaceinvaders finds and selects any text that overlaps drawing geometry.

AutoCAD offers several options for making sure text and mtext is not blocked by other geometry. Starting in AutoCAD 2005, you can assign Background Mask as a text property to mtext and dimension text. Select the text, then open the Properties palette. Under Text, enable Background Mask.

Caption: Turn on Background Mask to mask objects that overlap your text objects.

All lines near and under the text entity will automatically be masked. If objects still appear above the text, bring the text to the front with the Texttofront command.

Caption: Results when Background Mask is turned on.

In previous versions (pre-2005), you can use the Wipeout or Textmask commands to create a mask behind the text, then adjust the drawing order so that the text and mask appear on top of any underlying entities. Both Wipeout and Textmask began as Express Tools.

Select Wipeout from the Draw menu or by typing Wipeout at the command line. You are prompted to Specify first point to draw your wipeout object. Once you do so, continue to pick points until you’ve defined a closed shape, then pres Enter. You can also choose the Polylines option to convert an existing closed polyline into a wipeout object or the Frames option to change the visibility of the wipeout frames. Note that the Frames option will affect all wipeouts in the current drawing. The visibility of frames can’t be individually controlled. Also keep in mind that when frames are turned off, you can’t select wipeouts. That means frames must be on in order to move or modify a wipeout. You may also need to run Texttofront if your text ends up behind the mask.

Caption: The one advantage of using Wipeout is that you aren’t restricted to rectangular masks.

To run Textmask, make sure the Express Tools are loaded, then select Textmask from the Express Tools / Text menu or type Textmask at the command line. AutoCAD will prompt you to select the text you want to mask. It will also display current settings for Offset and Masktype. Type one of those settings at the prompt to change it. For Masktype, you can choose from Wipeout, Solid, or 3Dface. Once you select the text, AutoCAD will automatically apply the mask. Again, you may need to invoke the Texttofront command to bring your text in front of the mask.

Caption: The Textmask Express Tool automatically applies a rectangular mask.

If you are using AutoCAD 2005 or up, it’s best to use background masking instead of a wipeout. Certain printer drivers may print wipeout objects as black boxes rather than white or background-colored objects. Wipeout objects may also look perfectly fine in a PDF file, but when that file is printed, they come out black because of the printer driver used. Problems have also been reported when using Textmask on annotative text.

The workaround for wipeout objects is not so simple. You could use a hatch shape with a solid fill that has a unique color assigned, then in the CTB file, map that color to your desired color with shade set to 0 (zero).

AutoCAD offers several different options for creating blocks. All produce the same results. The one you pick will depend on your work style and the type of block you are creating.

Copy and paste. This is the simplest method. Just select the entities you want to turn into a block. Right-click and select Copy or Cut from the shortcut menu that appears (or just press <Ctrl>+C or <Ctrl>+X). Right-click again and select Paste as Block (or press <Ctrl>+<Shift>+V). AutoCAD will prompt for the insertion point. If you want to reuse the block or have others use it, other creation methods will give you more control.

Caption: Once you select and copy the objects that make up your block, right-click and select Paste as Block.

Block command. You can use this to convert existing entities in your current drawing. Type Block at the command line. The Block Definition dialog box displays. Here you can name your block and specify a base point (the point that will fall on the insertion point specified when the block is inserted). Under Objects, specify the entities to include in the block. If you click the Retain button, the objects you select will remain as they are in the drawing. Select Convert to Block to convert them to a block. Select Delete to delete them once your block is created. Options under Behavior allow you to make the block annotative, scale it uniformly, and explode it.

Caption: Block Definition dialog box. What you see may vary depending on your version of AutoCAD.

Wblock command. Wblock is short for Write Block. As its name suggests, it creates a new drawing file from the objects you select. The drawing file can then be inserted as a block. This approach is best when you are using block libraries or sharing blocks with other users. Wblock works in much the same way as the Block command. You specify a base point and the objects you want to include in the drawing (note that you can also write the entire drawing as a block). Provide a name and location to store your new drawing.

Caption: Write Block dialog box.

Block Editor. The Block Editor is an environment dedicated to block creation. You will need to use the Block Editor if you want to create dynamic blocks. Launch the Block Editor by typing Bedit at the command line or by selecting Block Editor from the Tools menu. You can also select any block and right-click to bring up a shortcut menu that lists the Block Editor.

When the Block Editor opens, you can either select an existing block to edit or create a new one from scratch. Note: If you’ve already drawn a block using the Block command, check the Open in Block Editor box in the Block Definition dialog box to have the Block Editor open automatically with your new block displayed.

Caption: Create or edit blocks in the Block Editor.

Caption: The Block Editor provides tools for drawing blocks and assigning dynamic properties.

When you’re done, select Save Block to save your block definition or Save As to create one with a new name. The origin (0,0) in the Block Editor represents the insertion point of your block. Move your geometry relative to the origin to change the insertion point.