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RE: ACAD Protection

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Very well put.  In industrial work clients often contract for the full cad
file (prepared to their specification) to be delivered so that they can
maintain a drawing data base of their plants.  Furthermore they often
stipulate that they will hold the copyrights to the drawings produced.

Ed Marshall, P.E.

> -----Original Message-----
> From:	Mark Middlebrook [SMTP:markmid(--nospam--at)]
> Sent:	Friday, January 08, 1999 2:04 PM
> To:	'SEAOC List'
> Subject:	Re: ACAD Protection
> The "turn a DWG file into a PLT file" method of drawing protection is
> useful to know about, but it's device-dependent (i.e., the recipient needs
> to have an output device that's capable of accepting the plot file) and
> may not serve the client's needs.
> A PLT file is a simplified vector representation of your AutoCAD drawing.
> The PLT representation contains vectors and instructions for how to show
> those vectors (line thickness, color, screening, and any other special
> effects), and that's about it. Layer information is absent. Text is
> converted to vectors. Drawing structure (blocks, xrefs, etc.) is gone.
> Essentially it's a plotted representation of your drawing in electronic
> form.
> If the recipient has an output device that understands your PLT file
> format (often HP-GL/2, the most common HP plotter format), then he can
> send the plot files to that device and get plotted drawings. If she has a
> piece of software that reads HP-GL/2 files, she may be able to view the
> plotted representation on the screen. With such software, she also might
> be able to convert the PLT to a different format (e.g., DXF) and bring it
> back into AutoCAD. But the result back in AutoCAD will be a pale shadow of
> your original DWG file (because of the loss of layers, text strings,
> drawing structure, etc.). That's why people often advocate sending PLT
> files as a means of drawing protection.
> However, the client who asks for AutoCAD drawings often is interested in
> doing something more than just plotting. Sometimes that "something more"
> is legitimate (e.g., electronic coordination, or full electronic submittal
> to the client). On the other hand, the firm that generates the AutoCAD
> drawings has a legitimate concern that the drawings not be misused (e.g.,
> relied on uncritically for shop drawings, designs or details stolen...).
> In my view, the concerns of all parties involved are best addressed in the
> contract for design services, not by ex post facto attempts to protect the
> drawings. Your contract should state exactly what your deliverables are
> (both hardcopy and electronic) what they're to be used for, and what they
> *aren't* to be used for.
> - Mark Middlebrook