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Guide to Prepress

Started by DigitalCrapShoveler, January 20, 2012, 03:39:22 PM

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DigitalCrapShoveler

I'm working on a guide for Prepress. It's been in the works for some time, but I am getting back into it. We may or may not print it as a resource for customers. I'd like you all to read through and tell me if I am going in the right direction. All comments are welcome...


File Formats

With applications changing and become more intuitive, designers as of late have become somewhat confused. In the past applications like Quark and PageMaker made sure that if a file format was not printable, you could not import it. Now, with applications accommodating the print designer as well as the web designer, file formats such as native PSD, GIF and JPEGs have become commonplace. The mistake that is most made is the treatment of file formats as a preference and not a need. Listed below are a list of file formats. If your preferable file format is not listed, then most likely it is because it is not supported. Each file format has a specific purpose, your job is to choose the correct one based on intent.

TIFF: Tagged Image File Format. The most common file format for straight 4 color with no effects. TIFFs should be set up as followed: Flattened, no extra layers, no extra channels beyond the CMYK, no paths, no LZW compression and 8-bits per channel. When saved make sure you are not attaching a color profile, since most printers manage all color profiles internally.

EPS (Bitmap): Encapsulated Postscript File: This file format is very versatile, but also very complicated. There are several different ways an EPS file can be treated. If you are implementing a clipping path and are dealing with a RIP that cannot handle transparency, then this is the file format for you. If you are creating Monotones, Duotones, or Tritones, then you would choose EPS. EPS files should be set up like this: Flattened, no extra layers, no extra channels beyond the CMYK or spot colors, no  JPEG compression and 8-bits per channel, transfer function and halftone screens should always be disabled. When saved make sure you are not attaching a color profile, since most printers manage all color profiles internally.

JPEG: Joint Photographic Experts Group. JPEG is widely received by the designer as the savior of file formats, mainly because it uses a variable compression algorithm that can save a lot of time and hard disk space. What is a JPEG? In simple terms a JPEG is a file format much like the EPS or TIFF except it has built-in compression. This compression has a variable slider that can determine how much compression is applied. A numerical range value from 1 being the smallest to 10 being the largest. The compression works like this: each pixel in a bitmap is analyzed. The surrounding pixels are averaged and assigned a numerical value, then deleted. This value is written into an attached log that keeps track of this data and when the file is expanded, (when printed) the pixels are reinstated based on the numerical value written into the log. The more the compression, the more pixels are deleted. Here's the catch...this log cannot only be corrupted causing pixel degradation, but due to it's nature a JPEG can be compressed too much and the file becomes unusable. JPEG compression uses what is called "lossy" compression, meaning it is averaging pixels, so the original data is being changed. LZW is very similar, only using a different algorithm to compress. The only true data compression without data loss is the ZIP compression. Most printers frown on the use of JPEGs because of their instability in the printing process. Generally used in web development.

PSD: Native Photoshop Document. This file format only recently became printable and is supported in many of the newer versions of layout and vector applications. PSD files differ from other file formats because of it's versatility. It can have multiple layers, multiple channels and paths, and be a fraction of the size a TIFF or EPS (bitmap) flattened would be. It also can be manipulated in some instances in the application it is imported into. However beneficial the PSD file format seems, it also can be problematic. The common misconception of PSD files are that since Adobe created Photoshop, Illustrator and InDesign that all these files are 100% compatible, not true. A PSD file needs to be treated as any of the other file formats regardless of the software manufacturer. The best thing to do when setting up PSD files, is to save two different versions, one being a "working file" with all layers with layer effects, i.e.: drop shadows, embossing, etc., intact and one with all layers merged, deleting any unwanted data, i.e.: channels, paths, etc.. They can be unflattened with a transparent background, but as said before, merge all layers and delete all unused data before importation. If you plan on using this format, include all fonts...just in case.

GIF: Graphics Interchange Format. Popular file format for LZW compressed raster graphics data, developed by CompuServe. It should only be used in web development, and is not suited for high resolution printing.

PDF: Portable Document Format. The PDF is often the choice of designers because of it's independence and versatility. PDF is one of the only file formats that is stand alone. Meaning it can be created from any popular desktop application, and regardless if the native application is resident or not, can be printed. For example, you have built a file in Multi-Ad Creator and export the file as a PDF, your printer does not have to own Multi-Ad Creator to print this file in high resolution. The drawback to PDFs are; they are only as good as the designer creating them, and since PDFs are independent of any application, it often ties the hands of Prepress when changes come into play. If you have problems with your file in it's native format, your PDF will have the same problems. If you do not embed your fonts, meaning the font is resident in your PDF, type changes can be quite difficult, if not impossible. If your images are RGB and/or low resolution, they will be so in the PDF. Every click box, and set up routine in the PDF exportation dialog are very important. If one of them is not correct, the PDF can become problematic. The best thing to do when supplying PDFs to your printer, is to talk to your printer about how to set up a PDF, (they often have settings for customers based on their preferences.)

DCS 1.0: Desktop Color Separations. This file format reacts exactly the same as an EPS (bitmap), but with a one difference, it creates a preview file, or thumbnail for placement and four individual high resolution channels for the cyan, magenta, yellow and black. The high resolution individual channels only come into play when separations are created via postscript. The advantages to this file format are quick placement and maneuverability within the application. The disadvantage; it is not supported in a composite workflow, which most high resolution printing is done.

DCS 2.0: Desktop Color Separations. Very similar to the DCS 1.0 format, but supports spot color separations within Photoshop. The file in question is built with the traditional CMYK channels and/or any number of additional spot color channels. This format is definitely for the advanced user. Not many applications support this format, so be careful as to when you use it. If a composite workflow is being utilized, DCS 2.0 files need to saved as a composite, NO desktop color separations. This ensures your file is saved in a composite form with multi-channel capabilities. The usefulness of this format has been replaced by the PSD format, so it probably should not be used.

As always using any file format that you do not understand is not a good thing. Call your printer to make sure they support the file formats you prefer before sending files their way. Good communication will insure clean output and happy Prepress operators.

Extensions

Extensions are very important in Prepress. Not only does it give the operator an idea of what kind of file he/she is dealing with, but it also keeps everything conforming. All your files main or support should have an extension attached. Believe it or not saving files without an extension can cause problems. In Windows, if there is no extension attached, files become unknown or "generic." Macs are a little more forgiving, but can cause havoc on occasion. The best way to set up files - always save an extension to avoid confusion. As said many times, it is better to have too much information than not enough. Look at the example below, on the left is a file with pertaining support and to the right is the same file correctly named with extensions.

WRONG   CORRECT

Brochure   Brochure.indd
Art      Art.tif
Logo   Logo.eps

Most applications will attach an extension automatically, but programs like Photoshop offer the option to save without. When files are packaged, collected for output or saved for service provider and burned to CD or DVD, the link between the main file and the support files are often broken. When Prepress has to reestablish these broken links, it makes it far easier to accomplish this when there are extensions present.

Listed below are some of the more common extensions we in Prepress encounter. This is not by any means a comprehensive list, but it will give you a better understanding of the files we receive.

PS   Postscript
FH3   Freehand Version 3
FH4   Freehand Version 4
FH5   Freehand Version 5
FH7   Freehand Version 7
FH8   Freehand Version 8
FH9   Freehand Version 9
FH10   Freehand Version 10
FH11   Freehand Version MX
FHMX   Freehand Version MX
PM4   PageMaker Version 4
PM5   PageMaker Version 5
PM6   PageMaker Version 6
PM65   PageMaker Version 6.5
PMD   PageMaker Version 7
INDD   InDesign
PSD   Photoshop Document
CDR   CorelDraw
PUB   Microsoft Publisher
DOC   Microsoft Word
XLS   Microsoft Excel
PPT   Microsoft PowerPoint
ART   Adobe Illustrator 88
AI   Adobe Illustrator
AI3   Adobe Illustrator Version 3
AI6   Adobe Illustrator Version 6
AI8   Adobe Illustrator Version 8
AI9   Adobe Illustrator Version 9
QXD   Quark XPress
RTF   Rich Text Format
TXT   Text Document
PDF   Adobe Acrobat
 
Dos and Don'ts

Below are some general rule of thumb tips for proper file preparation.

1.   Set up all heavy areas of black in a rich black. Talk to your printer on their preference.
2.   The combination of all four colors should not exceed 300% total ink coverage. When files exceed this limit it takes longer to dry after printed and can destroy a deadline.
3.   Always include all fonts and support with a native file. Do not assume because you have built your file with the font Times that we have it also. Times can be different depending on the platform created, the year it was created and the company that manufactured it. Even the resolution of you monitor can cause Times to reflow, so ALWAYS include your fonts.
4.   Before creating any PDFs, get your printer's settings
5.   Never pull images off the Internet and expect good results. The web displays images at 72 DPI about 228 DPI below the minimum tolerance. If pixelization is the effect your looking for, then by all means go ahead.
6.   NEVER copy files from one application and paste into another. Aside from text, files created this way are almost worthless. Always use Place or Import files to maintain a good link to support.
7.   Rotate or crop bitmap images before importation.
8.   Place bitmaps at 100% size. Scaling a high resolution bitmap image at 200% makes it low resolution, this is called "upsizing." Scaling a 72 DPI file below 30% makes it high resolution. Example: A 350 DPI image placed in InDesign at 300% makes it 117 DPI. A 100 DPI file placed in InDesign at 10% makes it 1000 DPI.
9.   If converting fonts to paths or outlines, always include a file that is not. This insures Prepress can make type changes if they are needed.
10.   All files need .125 bleed for any image extending beyond the trim margins. This gives tolerance for files in our bindery. Cutting and folding causes images to shift due to paper thickness, humidity, temperature and substrate, with minimum bleed, these issues become more compliant.
11.   When setting up files, all type should be .125 inches inside the trim. As said above, this allows for certain leeway in the bindery.
12.   Always inspect every proof like it was the first. No matter the revision, every proof can have potential problems. Check for wrapping, size, color and pagination before signing off. You and you alone are responsible for problems    after sign off, so make sure you are sure.
13.   COMMUNICATION!!! Ask if you are not sure, ask if you are. Never assume your file is exempt from problems. Just because ACME Printing printed your file with no problems, doesn't mean your new printer will. Every printer does things a little different because of machinery, output devices and staff.
14.   When sending files for printing, only include on disk the files we need. Do not include scans of your dog, your MP3 collection or anything else that could potentially confuse the job.
15.   NEVER send the only copy of your files. Disks can be dropped, lost, damaged or corrupted. Your printer cannot be responsible for human or elemental error.
16.   Avoid using the color Registration or Auto for blacks. These colors are 100% of all four colors exceeding 300% ink coverage, and are very difficult to keep in exact registration. Small type can end up with a colored halo if not caught prior to output. Microsoft applications are notorious for this, especially when copy and pasting. Double check your color palette for these colors and fix if they are indeed present.
20.   Convert all your full color images to CMYK. RGB is not a color space used in printing. RGB, or Red, Green, Blue is how how we as humans perceive color in the visual light spectrum. As an example of how different RGB is to CMYK, 100% of Red, Green and Blue make white. The combination of 100% CMYK, makes mud. RGB uses light as the base for this color space. Paper has absolutely no illumination whatsoever obviously, so RGB will not work. If you set your files up in RGB, we will fix them, but you will pay for it.
21.   Take the time to double and triple check your files. Whatever you do not do, Prepress has to do, and you will be charged for it.

I have a lot more to do, but this is what I have so far. Thanks for the help.
Member #285 - Civilian

David

good god man!
I need to get my glasses fixed now.

I haven't read it all, but it looks good.
As a funny aside (it's funny now, but it pissed me off at the time).
I worked on a Prepress bible for over a year, getting all the processes and workflows, each machine and it's innards, etc.
We then went through the ISO certification and it all got shitcanned, because it was more of a "procedural" documentation and you can't have that with ISO.      :hangme:
Prepress guy - Retired - Working from home
Livin' la Vida Loca

t-pat

I did this a few times. I still feel it was wasted effort.

Rule #1: Nobody fuckin' READS
Rule #2: You read this far? Gads man, you must be a nerd!
vdp donkey
gmc inspire • sarcasm while you wait

Ear

That is an awesome effort, man.

Gotta say, I agree with the-pat. If you read that and are able to understand it, you are probably at a point where you don't need to read it.  :laugh:

Rule #3: Gnubler will read half of it, post a  :sleepy: and ask if you're slow.  :popcorn:
"... profile says he's a seven-foot tall ex-basketball pro, Hindu guru drag queen alien." ~Jet Black

David

#8 - "Effective output resolution" is the actual name of that scenario
Prepress guy - Retired - Working from home
Livin' la Vida Loca

born2print

You forgot .prn and .docx formats  :angry:
How will I laugh tomorrow...
when I can't even smile today?

t-pat

I don't mean to be a naysayer and I know the frustration of what passes for print ready files these days. Valiant effort and maybe you're in a position to actually enforce it, sadly I'm not because we're whores and take just about anything. We say "can't" and sales says "will"
vdp donkey
gmc inspire • sarcasm while you wait

DigitalCrapShoveler

Quote from: born2print on January 20, 2012, 03:59:51 PMYou forgot .prn and .docx formats  :angry:

I have things to add, this is just the beginning.

I plan...  :laugh: to set it up as a book. A guide for sales to give to their customers. It will be worded as a design tool with tips and procedures as well as be visually pleasing displaying different finishes we offer as well as some die-cutting and other after print effects. Each leaf will offer a different substrate to further illustrate what we can do and the various ways ink interacts with that substrate.

What do you think? I haven't shown it to Management yet, but they have been on my ass about getting something out there. This is just the start.
Member #285 - Civilian

gnubler

I might use parts of it for our CSRs...who know about as much about printing as our customers.

Hi Ear :sleepy:
Hicks • Cross • Carlin • Kinison • Parker • Stone •  Colbert • Hedberg • Stanhope • Burr

"As much as I'd like your guns I prefer your buns." - The G

Quote from: pspdfppdfx on December 06, 2012, 05:03:51 PM
So,  :drunk3: i send the job to the rip with live transparecy (v 1.7 or whatever) and it craps out with a memory error.

Member #14 • Size 5 • PH8 Unit 7 • Paranoid Misanthropic Doomsayer • Printing & Drinking Since 1998 • doomed ©2011 david

born2print

Quote from: DigitalCrapShoveler on January 20, 2012, 04:14:57 PM
Quote from: born2print on January 20, 2012, 03:59:51 PMYou forgot .prn and .docx formats  :angry:

I have things to add, this is just the beginning.

I plan...  :laugh: to set it up as a book. A guide for sales to give to their customers. It will be worded as a design tool with tips and procedures as well as be visually pleasing displaying different finishes we offer as well as some die-cutting and other after print effects. Each leaf will offer a different substrate to further illustrate what we can do and the various ways ink interacts with that substrate.

What do you think? I haven't shown it to Management yet, but they have been on my ass about getting something out there. This is just the start.
Not sure, I've only read it twice.
J/K, I like it, and I think I would add the importance of a laser mockup. I published a sheet and used to hand it out, back when I still had hope, the 10 reasons we need lasers ©
How will I laugh tomorrow...
when I can't even smile today?

DigitalCrapShoveler

Quote from: born2print on January 20, 2012, 04:23:57 PM
Quote from: DigitalCrapShoveler on January 20, 2012, 04:14:57 PM
Quote from: born2print on January 20, 2012, 03:59:51 PMYou forgot .prn and .docx formats  :angry:

I have things to add, this is just the beginning.

I plan...  :laugh: to set it up as a book. A guide for sales to give to their customers. It will be worded as a design tool with tips and procedures as well as be visually pleasing displaying different finishes we offer as well as some die-cutting and other after print effects. Each leaf will offer a different substrate to further illustrate what we can do and the various ways ink interacts with that substrate.

What do you think? I haven't shown it to Management yet, but they have been on my ass about getting something out there. This is just the start.
Not sure, I've only read it twice.
J/K, I like it, and I think I would add the importance of a laser mockup. I published a sheet and used to hand it out, back when I still had hope, the 10 reasons we need lasers ©

Oh yes, lasers, how could I forget. I wrote this yesterday, I'm still writing things down to add. The problem is, I can't stop thinking of things to add and at some point it will be WAY too much. Since the guide will be two part, one as a guide and the other to show what we can do... I'm hoping it will stimulate the eyes enough to WANT to read it. A trick if you will.

What do you think about including a CD with our color settings and PDF settings? Maybe a digital copy of this presentation as well? Maybe I'll just stick to a URL the customer can access that will have these files available for download at any time. Still working the bugs out.
Member #285 - Civilian

born2print

URL or even a PURL seems the way to go these days, seems kind of "AOL-ish" to presume to send CDs out?
Good stuff brother!
How will I laugh tomorrow...
when I can't even smile today?

DigitalCrapShoveler

Quote from: born2print on January 20, 2012, 04:33:58 PMURL or even a PURL seems the way to go these days, seems kind of "AOL-ish" to presume to send CDs out?
Good stuff brother!

Good point. Thanks for the input, sir. Invaluable.
Member #285 - Civilian

t-pat

may as well add some of my pet peeves.

Make the damn document size or artboard the trim size you want back from us. Don't build stuff on oversize or arbitrary sized documents/artboards. USE the artboards in Illy if you have fronts and backs in one file, put them on artboard 1 and artboard 2.

Make all FPO/Dieline/Laser Text/foil/emboss/deboss/perf/score/slit/anythingthatdoesntprint/ in a spot color, on it's own layer.

USE LAYERS to isolate background from text from images. Don't put together a piece with everything on one layer - especially if you have a background, images, text, laser copy, dieline, foil stamping, or anything that is not ink on paper.

vdp donkey
gmc inspire • sarcasm while you wait

DigitalCrapShoveler

Quote from: t-pat on January 20, 2012, 04:55:05 PMmay as well add some of my pet peeves.

Make the damn document size or artboard the trim size you want back from us. Don't build stuff on oversize or arbitrary sized documents/artboards. USE the artboards in Illy if you have fronts and backs in one file, put them on artboard 1 and artboard 2.

Make all FPO/Dieline/Laser Text/foil/emboss/deboss/perf/score/slit/anythingthatdoesntprint/ in a spot color, on it's own layer.

USE LAYERS to isolate background from text from images. Don't put together a piece with everything on one layer if you have a background, images, text, laser copy, dieline, foil stamping, or anything that is not ink on paper.

Keep going... :wink:
Member #285 - Civilian