Locking Exported Drawing Files

Advice on how to transmit CAD drawings so that the viewer cannot alter the files. February 12, 2010

Is there a way to send a drawing in DWG format where the receiver is unable to make changes to the file? I am having problems with copyright and need to be able to send drawings without the receiver having the ability to change the drawing in any way.

Forum Responses
(CAD Forum)
From contributor S:
If youíre sending your recipient a DWG file, you basically giving an authorization to modify it. Convert it to PDF. They will not be able to do changes to it in PDF format.

From contributor M:
An easier way that is a pretty good lock is to insert it as an MINSERT into a blank drawing. They are more difficult to modify and most users don't mess with them. If you would like to pay, I would also recommend Cadlock.

From contributor J:
Did you apply for a copyright from the U.S. Copyright Office and receive a copyright from them? If you just put a copyright on a piece of paper or do a poor manís copyright they really donít hold up to well in court. If you are really concerned about a copyright you need to apply for one then you will have the law behind you, the only thing is that a drawing of a widget needs to have a patent because you are protecting the object drawn not the paper its drawn on. Patents are expensive. You should research what can be copyrighted and what cannot. Other ways to protect your self is to have a written agreement before you start the project stating who has the rights to it. If you are drawing then sending it to several others then you need a release agreement stating ownership and other pertinent information to protect yourself. The Cadlock software is $300 adobe standard is about $300 but you can find it for less if you search. I prefer the PDF myself. There is all kind of free PDF printer software you can find on the net. If you donít want them changing anything or you donít trust them use a PDF and a release agreement.

From contributor S:
As far as I know, anything that is printed, drawn or otherwise graphically represented by its author (protection of original designs) is automatically protected by copyright law of the United States and does not require (you can if you want to) registration with U.S. copyright office. Patent is different and not necessary needed for shop drawings or Architectural projects, unless there is something unique in them.

Even if work is registered with office and protected with a million laws, if somebody wants to knock it down, there is not much we can do prevent this somebody from doing so.

From contributor P:
I'm trying dwglock from dwgsoft.com. Our department keep the original DWG and send our clients the copies generated from the dwglock program.

From contributor P:
I send all my drawings PDF no worry about someone changing them and you can print right from Autocad to a PDF file, nothing to buy, no add onís!