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ibler



Number of posts : 112
Location : cebu
Member since : 2007-06-05

PostSubject: overprints / trapping   Thu Jul 16, 2009 9:41 pm

A very curious thing happened today. I know the answer is all in the settings but what specifically i do not know. Anyway this is my story...

I created a layout on Illustrator cs2 for filming. Colors were all spot and defined properly in illy. The traps and sets were carefully set and checked. i even checked the separations preview in Indesign. The ai file was then exported as .eps with overprints preserved.

So I send it out for filming.

The operator of the imagesetter is used to gravure screens and settings. Every time I send him a file, he just uses the default for offset. My files will just then be opened in the rip software (yup, he doesn't review the file) and queued.

When I got the film, I noticed that the register marks that I made did not appear. And some of the overprints did not come out as overprints! In short . . . disaster!

Since I couldn't use the film and i needed it asap, I had the file re-filmed with a service bureau. And it came out right - overprints, traps and all. 30 mins flat from pick up to delivery! (of course Cebu is just small hehehe)

Conclusion:
1. Settings must be wrong.
2. Service bureau guys know what they're doing.

Recommendation:
1. Replace imagesetter operator.
2. Stick with service bureau.
3. Buy own imagesetter.
4. Save up for ctp.
5. Study nursing and work abroad!!!

Have a good day everyone!!!
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Sandman

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Number of posts : 404
Location : Middle East
Member since : 2007-11-21

PostSubject: Re: overprints / trapping   Fri Jul 17, 2009 4:15 pm

Hi ibler.

Go for a pdf/x workflow and then make preflighting mandatory before sending it for film output. If you're pdf is certified then at least you know you're file is 100% print ready. All pdf/x variants accept spot colors.

May be you would also want to contact the tech guy of your service bureau and pay him extra to check out your RIP settings and also to give a small training for your CtF opertor/s.

After which, create a work procedure that is realistic and easy to understand so that you can standardize your workflow.

My thoughts only.

Larry
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ibler



Number of posts : 112
Location : cebu
Member since : 2007-06-05

PostSubject: Re: overprints / trapping   Sat Jul 18, 2009 12:18 am

Sir Larry!!! How are you!?

First off, it's not my imagesetter. It's my uncle's. Im just helping him to maximize his machine. That gives me an almost zero chance of tinkering with the unit. And a close to impossible chance for the service bureau guy to tinker with the settings.

Another problem is the operator. He's not very comfortable working outside of the parameters that he know. And because they're working with gravure, I dont think mastering offset settings would help him with his work.

One question though:

How different would a pdf file behave from an eps file in this case because . . .

1. I checked all traps and overprints iin illy and indd and they are all good. In illustrator, the overprint preview showed that all traps overprint. In indesign, using the separations preview, the traps again showed that they overprint.

2. The operator was able to output the spot colors thus the machine recognized the defined colors.

3. Would an "override print settings" in the RIP discard all my defined print settings and use the RIP's print settings instead. And this is my hunch because I made a simulated separation on my ps printer and again the traps and overprints were there.

Anyway, thanks and good to hear from you again!
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presstech

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PostSubject: Re: overprints / trapping   Sat Jul 18, 2009 1:09 am

Hi Ibler,

I agree with Larry that you should used pdf/x. Your uncle's imagesetter uses an EagleRip which we installed about 3 years ago and it handles pdf files very well. While the rip's specs say that it can process eps files, I have always, as a standard procedure, downloaded ps or pdf files to rips and never eps.

Incidentally, the default setting in EagleRip is:
override overprint in job - ON
overprint mode - BLACK ONLY

This could explain the missing overprints.

EagleRip has a very good preview mode. The preview should have clearly shown the missing overprints and register marks before output.

The question is - did the operator preview before output? Sleep
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Sandman

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PostSubject: Re: overprints / trapping   Sat Jul 18, 2009 5:20 pm

Coordination is key. Before we send any file for output technical specs should be ironed out first. For starters questions we should ask are as follows:

Do they prefer eps, ps or pdf or pdf/x;
Can they handle pdf/x files;
If so, which version (pdf/x-1a; pdf/x-3; pdf/x-4);
Can the RIP handle transparencies;
Is there a trapping software in the RIP;
Is there auto preflight and auto correction in RIP;
Is in-RIP trapping enabled;
etc..

A valid pdf/x file shall indicate if file has trapping enabled (True) or doesn't have one (False). This will serve as a guide for the CtF or CtP operator if he needs to apply in-house trap settings or use the trapping from the client.

A valid pdf/x files shall have an output intent specified so the prepress guys will know if they need to "color manage" the file or to simply feed it to the RIP without any color transformations.

The operator of the imager definitely needs to know these things. But the file sender should also be responsible to ask the above-mentioned questions just to ensure the final output is what the file sender expects.

As previously said in another post, the output (y) is always deterministic as long as all input parameters (x) are defined and requirements met.

My thoughts lang po.
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ibler



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Location : cebu
Member since : 2007-06-05

PostSubject: Re: overprints / trapping   Sat Jul 18, 2009 11:26 pm

Sir presstech... went to the plant this morning and as you mentioned, the rip was in "overprint black only" default. There the answer.

So I got then to the next question . . . because the operator said that he can process pdf files among others . . . I asked him which version he is comfortable working with.

The thing is he's not sure. This means that I will have to read up on the literature about eaglerip. So I'll be giving a free training into pdf workflow huh sir larry. btw how much is the going rate for such a training? maybe we could organize one here sir larry!

Thanks Sir Presstech and sir larry!

I'll post another rip question in another thread...
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Alex Dulay



Number of posts : 108
Location : Manila
Member since : 2008-12-30

PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 2:11 am

although, EagleRIP says that it can accepts pdf > 1.3, I believed if you are to go PDF, you will choose between pdf 1.3 or 1.4 of pdf/x because of transparencies issues.

To be successful with PDF, one must follow "standards" otherwise it will be just another file format that the RIP may not interpret successfully.

Just my 2 cents.
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Sandman

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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 10:20 am

Hi ibler. Be careful because you might be teaching them on how to output your files correctly....which is good for you....but can be bad for other customers.

The procedure you will be teaching them can be advantageous for your proprietary workflow but might adversely affect other jobs that is prepared differently.

Your training should prepare them accept different types of workflow without any hassles. These files can come as:

. Native Illustrator files
. Native InDesign files
. eps
. ps
. pdf
. pdf/x (1a, 3 or 4)

Chances are you might be required to create several hot folders (drag and drop) each with a specific setting depending on the incoming file...and the clients' output requirements.

Some tasks can be done manually or automatically at the application stage but some are better off at the RIP stage. Redundant tasks at the application and also on the RIP can be disastrous.

Depending on the RIP's capability (APPE based or not) some files are better sent off with transparencies....but some have to be flattened. Files requiring "trapping" at the RIP stage should have live transparencies...and not flattened.

Pdf/x-1a and Pdf/x-3 files are based on version 1.3 which is flattened. In this case they should require their customers to give them either Pdf/x-4 or any error free Pdfs with versions greater than 1.3.

Any improvement project should start with an in-depth audit of their file acceptance workflow. Test them how they accept different file formats. Check for loop holes.

Another important phase of any pdf/x training is preflighting....and also troubleshooting of non-conforming files.

Please PM me if you have some doubts on certain issues. I will be free til end of July.

Regards.


Last edited by larrysison on Sun Jul 19, 2009 10:35 am; edited 2 times in total
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ibler



Number of posts : 112
Location : cebu
Member since : 2007-06-05

PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 10:27 am

Question:

I tried creating a pdf 1.3 file from illy. An error message came up in the dialog summary saying that there were issues about transparencies The file had several images with drop shadows). So I flattened the images, still in illy. But when I previewed the file in InDesign using the separation preview, the area where the drop shadows were located had a distinct blur/outline.

I also created a 1.4. The error dialog did not come out. However when the file was processed, file size (not sure if it was really file size but it can be located on the upper right hand of the EagleRip window) already reached close to 1gb. But the original file was only 5mb.

Any thoughts?
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ibler



Number of posts : 112
Location : cebu
Member since : 2007-06-05

PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 10:31 am

Sir Larry!

I guess you're right. But as far as this guy is concerned, I think showing him how to output my files correctly is a good way to start. Besides they're not really a full service establishment. But you have a very valid point.

As for my doubts, I'll post all of my questions here so that the other members can learn from your insights!

Thanks again!

p.s. when are you dropping by cebu? heheh
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Sandman

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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 10:33 am

I need to see your file but I'm here....you're there...hehehe. I don't have any software with me, ibler.

Please PM Alex Dulay on how you can send your files to him so we can run it through our system in Saudi.

Pero in Illy, try going to Raster Effects and set your resolution to 300ppi. Then in Transparency Flattener drag the slider all the way to 100% (vector). Tapos enter your output resolution exactly kung ano ang resolution ng CtF ng imagesetter (2,400dpi or 2,540dpi). Your gradient mesh naman puwede na mga 600.

This should help....I guess.

*** No time to go to Cebu. Sayang. Ikaw...kailan ka punta Bacolod. Masarap manok dito...lol!
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presstech

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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 11:02 am

ibler wrote:
Question:

I tried creating a pdf 1.3 file from illy. An error message came up in the dialog summary saying that there were issues about transparencies The file had several images with drop shadows). So I flattened the images, still in illy. But when I previewed the file in InDesign using the separation preview, the area where the drop shadows were located had a distinct blur/outline.

I also created a 1.4. The error dialog did not come out. However when the file was processed, file size (not sure if it was really file size but it can be located on the upper right hand of the EagleRip window) already reached close to 1gb. But the original file was only 5mb.

Any thoughts?

Hi Ibler,

if I remember correctly, the file size shown in the upper right hand is the size after ripping which should normally be a lot higher than the original pdf file. Don't let this bother you, since this is part of an internal process, unless you are going to output a 1-bit tif file instead of directly to the imagesetter or CtP.

The EagleRip installed on your uncle's imagesetter is version 4.0 which will process up to pdf 1.5. The latest version 4.2, which we recently installed at Manila Standard, handles up to pdf 1.7. sunny
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presstech

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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 11:11 am

Hi Ibler!

If you need a copy of the EagleRip manual, I can e-mail you the pdf copy which is only 4 mb. Just pm your email address.

BTW, I will be in Cebu in mid August. Maybe we can meet.sunny
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Guest
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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 11:24 am

Hi Sir Ibler,

IMHO

May I suggest you read this first before creating your pdf (www.pass4press.com).
I agree with Sir Larry that coordination is the key. That is the only way you can be sure of trouble free output. Letting the operator (ctf or ctp) know of the things he needs to check or at least making him aware that you do this and that to your file, and it needs to be honored.



Regards
Anton
TRIUNE GRAPHIX CORP.
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Sandman

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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 12:34 pm

presstech wrote:
Hi Ibler!

If you need a copy of the EagleRip manual, I can e-mail you the pdf copy which is only 4 mb.

Sir Fred, can I also have a copy of the manual so I can read in advance before making possible changes at MST. Thanks.
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ibler



Number of posts : 112
Location : cebu
Member since : 2007-06-05

PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 3:22 pm

Sir Presstech,

Thanks! Will pm you my email. This will be very helpful. At least this will save me at least one trip to the plant.

Are you dropping by my uncle's plant? we can meet there. Probably go out for coffee or something heheh. Will pm you my phone number.

I kinda figured out that the increasing file size was an internal process. But logic is beyond me to see that a 5mb file when "ripped" would go up to 1gb but an 8mb file was processed in just a few seconds.

But when you say don't bother with it then i won't. Smile


Shutter,
Thanks for the link. You're right, coordination is the key. Will try to develop a good workflow for them to adopt.

Downloading the book now as I type.


Thank again guys!!!

bounce
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presstech

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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 3:48 pm

larrysison wrote:
presstech wrote:
Hi Ibler!

If you need a copy of the EagleRip manual, I can e-mail you the pdf copy which is only 4 mb.

Sir Fred, can I also have a copy of the manual so I can read in advance before making possible changes at MST. Thanks.

Larry, Ibler

Send me an email and I will reply with the file of the manual attached. If you need it right away, send the email before 4 pm today. I will be leaving for Malaysia later.

My email is philprinting@gmail.com
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Alex Dulay



Number of posts : 108
Location : Manila
Member since : 2008-12-30

PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 4:37 pm

I kinda figured out that the increasing file size was an internal process. But logic is beyond me to see that a 5mb file when "ripped" would go up to 1gb but an 8mb file was processed in just a few seconds.

Just to give my thoughts on this:

RIPs that are not based on Adobe's PDF print engine still ends up into postscript code. Basically these RIPs are Postscript Level 3. PS3 includes codes that enable PDF file to be interpreted and then converted into PS3 codes. That explains the gigas internal processing especially with EagleRIP which is not an Adobe OEMs.
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Alex Dulay



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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 4:40 pm

The EagleRip installed on your uncle's imagesetter is version 4.0 which will process up to pdf 1.5. The latest version 4.2, which we recently installed at Manila Standard, handles up to pdf 1.7.

Sir Presstech/Larry,

Please inform me how good the new EagleRIP in processing tranparencies. I received an email from Awie that it rejected pdf 1.7.

Alex
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ibler



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PostSubject: Re: overprints / trapping   Sun Jul 19, 2009 9:34 pm

Now that explains it!

Thanks Sir Alex! I really thought something was wrong with the file. But how come another slightly smaller file was ripped in a short time... without the gigas shooting up?

If I remember correctly, the 1st file with the huge ripping was a 1.4 but the other file was a 1.3? Could that be it?
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Alex Dulay



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PostSubject: Re: overprints / trapping   Mon Jul 20, 2009 12:57 am

Sir Ibler,

My understanding is that it depends on the page elements. Files that have more vectors elements, layers, transparencies which include overprints/trappings, maskings and other specialized features like drop shadow effects from Illy and Indy will end more gigas. These elements are converted by Postscript into dots. You can confirm this by printing an Illy file to Postscript and PDF file. This is also one of the reasons for the clamor then for a PDF print engine.

PDFs are compressed files. Postscript based RIP decompresses PDF.

Alex
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Alex Dulay



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PostSubject: Re: overprints / trapping   Mon Jul 20, 2009 1:16 am

And btw,

One can create PDF files from the same source with different file sizes.

Alex
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ibler



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PostSubject: Re: overprints / trapping   Mon Jul 20, 2009 7:46 am

Thanks for the clarification Sir Alex!

Funny that the more you understand, the more questions that need to be asked. hehehe

Smile
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Sandman

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PostSubject: Re: overprints / trapping   Mon Jul 20, 2009 6:48 pm

ibler wrote:
But how come another slightly smaller file was ripped in a short time... without the gigas shooting up?

I agree with Alex that with more vectors and transparencies on your file interpretation in the RIP will definitely be longer. The RIP will have to interpret every node of your vectors and graphic elements with transparencies or masks before it can covert it into dots.

You can try experimenting different transparency flattener settings in Illy or Indy, by dragging the slider all the way up (vector) or all the way down (raster). Check the file size as well as the RIPping time. Generally, we prefer the slider to 100% vector when flattening transparencies.


Last edited by larrysison on Tue Nov 10, 2009 4:39 am; edited 1 time in total
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ibler



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PostSubject: Re: overprints / trapping   Mon Jul 20, 2009 9:11 pm

Will definitely spend more time on the computer.

Thanks again guys!!
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