Preventing the Big Purge

There are two kinds of offices.  Those who don’t know what the purge command does, and those who run the purge command every time they leave AutoCAD to check their email.

The difficult thing for me to teach people is that a few extra layers in your drawing (say, items from your standard layer list that aren’t in use right now) are OK, but a heap of last year’s inserted wblocks need to go.  There is a fine balance between keeping your drawing cleaning, and wiping out your template.

Click more to find out a trick to keep your important elements from being purged….

Civil 3D helps here, because if a linetype or layer is referenced in a style, it cannot be purged.  But even the most style-compulsive person (like me) cannot make a style for everything.

Or can you?

This tip comes from John Mayo over at Conklin Associates in Ramsey, NJ.  John has the unfortunate privledge of putting up with my presence for about three days a month (or perhaps it is the other way around?)

Turn your standard template (the one with your cogo blocks, linetypes, layers, etc. loaded into it) into a dwg.  Clean out all of the styles and remove any layers, block, etc that are already “locked” into the template.  You don’t want an entire duplication of your template, just the things that could be accidentially purged.  Better yet, create a new drawing from the acad.dwt and use the design center to bring those things in.  Make sure this drawing is clean (audit, etc.)

Insert this dwg into your template as a block into a point style.

Name the Point Style something so that you don’t confuse it with a real point style.

Purge your heart out every 3 minutes and you’ll never blow anything important away.


  1. John M. says:

    This whole experience has been nothing but a pleasure for us Dana. 🙂

    Let’s also give credit where it is due, this little trick was inspired when you helped me find out why Anthony G’s Super Secret Style Getter was working as expected. Thanks to you & Anthony.

  2. Dave says:

    I tried this but it did not work. Cool idea though. I created both a point style and lable style and created a point and point groupand applied the both styles. I was able to purge averything in the block yet the block still exists in the drawing.

  3. JohnF261 says:

    I’m old school. I remember the 64k of memory days. I purge early and often. I do keep a base drawing with all the purgable layers, etc. but instead of design center I insert the block…but when I’m prompted for the insertion point hit escape! Everything comes in with the definition but without any objects.

  4. John M. says:


    It’s tough to help without a file to review but, I would make sure that the block you inserted is still set to display as the marker in the new point style. I would also make sure that the block name does not match the file/template name to prevent circular reference issues.

    John M.

  5. John M. says:

    “I would make sure that the block you inserted is still set to display as the marker in the new point style”

    I should have phrased that better. You want the block assigned as a marker. I would keep the marker display off.


  6. John M. says:

    After re-reading this I know why it isn’t working for you Dave. The block you create (that will be assigned to the point syle) has to have an entity in the block with each text style,linetype or dimension style assigned to it.

    I have had kept separate dwg’s with everything in it in the past so our users can always get back the purged lines, fonts & blocks. My TxtSymLine.dwg has 66 blocks, about 30 lines (each with their own linetype), a dozen or so mtext strings (each with thier own text style) and some dimensions (each with their own dimension style).

    I can update this file easily by opening it & drawing a new object & modifying it to look & behave as desired.

    I then use this file to keep the main C3D templates current & to help other users update older dwg’s.

    We simply insert the file as a block & choose to update the block definition. All new objects stored in the block will be saved with the dummy point style. Note that this will not update existing definitions. AutoCAD by default ignores duplicate block def’s during an insert.

    With Annotative Objects in 2008 I plan on having quite a few new fonts, dims, etc. This will let me play with the TxtSymLine.dwg & update templates when ready w/o dragging & dropping individual objects in Design Center.

    It does work. 😉

    John Mayo