Tipster Eric Lynch tells us about the Wipeout command in AutoCAD, and how it can be used to mask out unnecessary linework without altering it.

"A quick way to hide unwanted items in the background without having to trim and lose all the information is to use the Wipeout command. It creates a masking block by drawing a boundary, or selecting a polyline as its boundary. You can put it on a non-plotting layer and send it below linework for a quick mask that can easily be manipulated without losing your lines to trimming."
 
Notes from Cadalyst Tip Patrol: Wipeouts can be useful — and dangerous. If their frame is turned off, they can't be selected. Many times I have spotted "blank" areas on a print, and spent hours trying to figure them out. To toggle Wipeout frames, type Wipeout on the Command line, then F, then type On or Off, according to what you want to do. If Wipeouts are used, it is a good idea to follow this tipster's advice and put them on a non-printing layer. They will still work, but the frames won't print, and you can edit them.