RE: [iText-questions] Re-Post: Line-Screen

[Bill Ensley]

My apologies Leonard,

 

I wasn't meaning to be rude.

 

I have been following the iText mailing list for some time and it seems

 

that the iText team is unaware of the other uses for PDF files.

 

PDF for Press is a totally different avenue that PDF for web or distribution.

 

Adobe has made many enhancements to the specification for the Printing Industry.

 

My shop works with dozens of PDFs daily, including many created by the iText Library by

 

our users.

 

I was simply trying to come up with a solution to a feature the iText lacks.

 

Halftones really are part of PDF.

 

Right now, I must export all of my iText PDFs to eps files and import those

 

EPS's into a program that lets me add a default Line-Screen (Halftone) so that

 

I can control how the output looks.

 

Adding the functionality to iText to set the default Halftone information

 

would be a great enhancement.

 

Thank you again

Bill Ensley

Bear Printing

www.bearprinting.com

 

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Bill Ensley
Sent: Monday, March 01, 2004 11:44 AM
To: iText Mail Group
Subject: RE: [iText-questions] Re-Post: Line-Screen

I'm afraid you are not understanding what a Halftone is.

 

I have been involved in printing for over 20 years

I use almost a complete PDF workflow in my shop.

 

You can set a default Halftone in a PDF,

we do it all the time from every program that creates PDFs that we use.

 

This is not about a Spot Function on objects, i'm not even sure what that means

 

When you print a PDF on a halftone device, be it a Laser-Printer or an Image-Setter that creates film for Press

you need a Line-Screen.

 

The output-device can set the screen, or it can use the embedded one in the PDF.

 

Just look at the print dialog for Adobe Acrobat!

 

It has a check box even Titled "Use Device Halftones"  if this is unchecked, the device

will use the embedded halftone information.

 

Below is code directly out of the PDf Reference

 

28 0 obj

    << /Type /Halftone

        /HalftoneType 1

        /Frequency 120

        /Angle 30

        /SpotFunction /CosineDot

        /TransferFunction /Identity

    >>

endobj

Thank you

Bill Ensley

P.S.  As for the most folks that don't need/care about it, that's just naive

-----Original Message-----
From: Leonard Rosenthol [mailto:[EMAIL PROTECTED]
Sent: Monday, March 01, 2004 10:34 AM
To: Bill Ensley; iText Mail Group
Subject: RE: [iText-questions] Re-Post: Line-Screen

At 12:52 PM 3/1/2004, Bill Ensley wrote:

Please refer to Adobe PDF Reference Guide
Line-Screens and Halftones are a HUGE part of PDF.

        I assume you are referring to the spot function which can be used to produce a line-screen LIKE result for certain object types, yes??  If so, then yes, I guess you could call it that - but it's not a full & complete "line screen" as needed in some printing processes.   That's why folks who are that anal about printing control will rasterize FIRST, then adjust the raster to match the screen, and then print the raster image.

If this library is going to be the best, and I think it can be
(I'll gladly help), it should include this feature.
 

        Sure, supporting spot functions as part of the creation for spot colors seems like a nice addition - you will need to it for all uses of spot (both raster & vector).  However, honestly, most folks don't need/care about it.  You'll find very few PDFs (for print) that actually have them.


Leonard

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Leonard Rosenthol                            <mailto:[EMAIL PROTECTED]>

Chief Technical Officer                      <http://www.pdfsages.com>

PDF Sages, Inc.                              215-629-3700 (voice)

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