Expert: Bob - 1/21/2008

Question
Hello,
I am an Engineer in training working in structural engineering.  I learned AutoCad in 1996 and have used it and ADT2007 continuously since then. I have significant 3-dimensional modeling skills using solids and other add-on programs like Hsb-Cad.  
Recently I sent some drawings to be plotted by a professional printing business in Bozeman, Montana.
My company plots in black and white only.  We use a special.ctb file for our printing which has always produced good results on our HP plotter and on other plotters in the area belonging to various architects.  But recently we have been working with a printing company which uses a Xerox 8850.  Now all our various shades of grey lines show up as extremely faint lines.  Our .ctb files have been manipulated so that original autocad linetypes 8 and 9, as well as  250,251,252,253,254 and 255 are set to color 'black' and are screened at 20%, 40%, 60% etc because we plot in black and white and this special.ctb file has been adopted as our 'standard'.  I sent the printing company .dwg files, .pdf files and finally .plt files. We installed their Xerox 8850 driver, always check the plot to file box, but still their Xerox 8850 plots the same faint grey lines. When I use the AutoCad preview, it shows the correct preview, but this preview obviously does not represent the .plt file that gets plotted. When I plot to our plotter it is fine like it always has been. Is there a viewer out there I can use to view the .plt files or do you have any other suggestions?  The printing company does not own a .plt viewer or even preview their drawings, and the architect on this project refuses to change printing companies so I am stuck using this printing company.  I really do not want to change my .ctb files because of the complexity of the job I am working on. (Tens of Xrefs, Large commercial projects).

Thanks,
Carl

Answer
Hi -- we are going to get a bit outside my knowledge here, so I am going to make some comments, and refer you to more help.

Before that-- a thought I had while finishing this up--
DID YOU TELL THE PRINT SHOP TO "PLOT BLACK ONLY"? I have experiences where that was needed to be asked. I would try sending one of the plts again with a question as to whether that can be done.

First, small error that you refer to color numbers as linetypes-- that might work internally, but it is not really accurate. And setting those eight shades of grey to plot black seems like not the best way, as the present result may suggest. I would use layers in color black, set to plot screened, myself.
Second, the fact that you sent a reprographer the drawing file, then pdfs perhaps shows a lack of experience in outside printing. One ONLY sends the plt. file, plotted to the correct plotter, if you ask me. (The dwg leaves it to the other to handle, so you dont know what the result is, and if bad, makes you look poor. The pdf wont necessarily print well in large scale)
Third --- My thought is that with less trouble than you have gone through, you could have modified a copy of your ctb file for this client. I also wonder how your drawings plot when xrefed by others.

But dont rely on me -- post your question in the AutoCAD plotting group, and someone there should be able to tell you why the (in my opinion) fudge in your plot style is working on your plotter, but not the remote plotter.
http://discussion.autodesk.com/forum.jspa?forumID=30
Good luck!

BOB

PS -- I am also good at 3D solids -- but I hope you threw out all you knew and started over when 2007 came out, with the amazing improvement in solids.
PPS -- for all the time you have spent, I wonder if FEDEXing one copy of each set and having it copied at the other end might not have been better.