[Gimp-user] Blueprint Style Effects?

[Garyfx <forums gimpusers com>]

I'm new to GIMP and need to create an effect from existing JPG images that look
like a simple blueprint of the image objects.  Specifically large trailers used
for hauling race cars.  The effect I'm after is not unlike the one on the
background of the gimpusers website.  Anyone know how to achieve this?  I've
attached an example of the effects here.
Thanks!

Attachments:
* http://www.gimpusers.com/system/attachments/163/original/Trailer_CADS.gif

-- 
Garyfx (via www.gimpusers.com/forums)