We have all referenced a file at some time, perhaps. Maybe you haven’t yet. I recommend it. It can help to keep drawing data current and accurate across a drawing set.
If you haven't, well I posted another tip on x-reffing (my spell check is going crazy with the red squiggle on x-reffing) a few days ago that provides a few tips on opening files that are referenced. Check it out: X-Ref Quick Tip
Let’s assume that you are referencing files. Good for you. How do you do it? What do you mean “how”? (Yes I am talking to myself. It’s ok, I do it all of the time.) What I mean is do you reference the drawing as an attachment or an overlay? HUH???? (Again, it’s ok that I talk to myself.)
In AutoCAD, when a drawing is referenced, there are two different ways to connect it to your drawing file. One way is as an attachment. The other is as an overlay. What’s the difference? Good question.
Attached files are just that. The data in the file will go with the drawing file it is attached to. On overlay is like Las Vegas, what happens there stays there. Let’s try to clear that up. I have a DWG file, it is file aa.dwg. It is my model file. I need to reference it in my drawing file, file name draw.dwg. I open file draw.dwg. I start the reference manager. I reference my model file (file aa.dwg) to show the linework in my drawing file. I have the choice of making it an attachment reference or an overlay reference.
When the model file is an attachment reference in my drawing file, that information goes with it if I reference the drawing file into another file. If I reference the model file into my drawing file as an overlay, and then reference my drawing file into a different file, that overlay file will not go into the third file. Clear on that?
Why would I choose one over the other? Best question yet. I would reference a file as an attachment if I need those two files to go together, everywhere. If I only need the data from the model to show up in the drawing file, but nowhere else, then an overlay. This will prevent circular references when attaching files and it helps in file management or drawing management procedures. It is often the case that I only need data from a certain file, but in order to create that file I needed the data from a third file.
Think about it. You might be saving yourself some work if you attach or overlay a file.