Brock Narum sent this background mask procedure that he uses in AutoCAD 2009. "Select the mtext and go to the Properties tool palette. In the palette under Text, there is a Background Mask option that allows you to use same color as the background and adjust the offset distance from text. The result is very similar to that of the Textmask Express command. The only difference is that mtext mask will automatically adjust the background mask to match extents of mtext height and width."

NOTES FROM CADALYST TIP PATROL:
This works in AutoCAD 2008 as well. Background Mask is a great tool for displaying text in areas of drawings that are very busy. It is superior to Textmask because it is part of the text object, whereas Textmask creates a blank image behind the text that must be moved with the text and is often left behind when users are unaware it is there. Be cautious with masking text because not all plotters can process this feature. If you find this to be the case with your own plotter, make sure the latest drivers and firmware are installed.

Follow-up: Mask Background
Jim Olszewski had this to say about the November 17 tip on the Background Mask feature:  "I know I'll be using it in the future! Another way to access this great feature is to right-click when mtext editing. The menu that opens has Background Mask as an option. You don't even need to highlight the text!"