Applied Color Theory Archive

Separations

Black on Dayglo Green (2005)
A list member asks for advice on how to handle brilliant extra inks.

Black Weight Is Inadequate (2007)
Members try to diagnose why shadow weight seems too light.

Blues, Purples, and JPEGs (2002)
Questions on the old problems of blues and CMYK lead into a broad discussion of JPEG quality, whether profiles whould be embedded, and the virtues of wide- and narrow-gamut RGB definitions.

Blue Turns Purple During Separation (2003)
Two separate threads on one of the biggest difficulties in making separations—deep blue areas in RGB that turn out purple in CMYK. Dan Margulis explains why the cure can be worse than the disease.

CMYK Minimum Highlight (2003)
What is the smallest dot that a press can hold? And how can it be controlled in pictures with critical highlight detail?

Crazy Gray Ramp in Newsprint Separations (2006)
Why the cyan is so much higher than the magenta.

Custom CMYK 1: Ancient? (2002)
An Adobe spokesman's contention that the "Custom CMYK" menu of Photoshop is obsolete attracts the ire of those who know better.

Custom CMYK 2: Asking Adobe (2005)
List members allege that Adobe has abandoned the CMYK community.

Custom CMYK 3: The Eurostandard setting (2005)
Why neutral balance can be deceptive.

Custom CMYK 4: How to Edit SWOP v2 (2006)
Dan reveals how to create alternate black and total ink generations for a profile that is supposed to be impossible to edit.

Custom CMYK 5: What Makes Adobe Tick (2007)
Analysis of the long-time hostility between printers and the Photoshop engineering team, noteworthy for an excellent final post by list member John Gallagher.

Custom CMYK 6: Five Pressroom Tales of Horror (2007-2008)
Think that commercial printers can be trusted to give accurate information as to how files should be prepared? In a period of less than three months, five threads develop independently, but they each cast doubt on the proposition.

Custom CMYK 7: Proper Black Channels and Surreptitious Conversions (2008)
This very long and instructive thread starts with a seemingly innocuous question about how to prepare files for an unknown commercial printer, given images with important shadow detail. It moves on to the question of how much the printer's advice is worth, and the revelation that some commercial printers are surreptitiously reseparating incoming files in order to save on ink costs.

Custom CMYK 8: Current Eurostandard Profiles (2009)
Diffficulties with supplied, uneditable profiles for European printing leads to another heated discussion of why Custom CMYK is necessary.

Dot Gain: Who's Responsible for Compensating? (1999)
A series of threads on dot gain, its ramifications, how it affects proofing, and who's responsible for compensating for it.

Drop Shadows and the Black Plate (2001)
How much black ink should an artificial shadow contain?

Drop Shadows and Black Redux (2004)
The perils and promise of making the drop shadow in black ink only.

Duotones Using Metallic Inks (2003)
The problems of proofing off-press for an ink that's rarely in use.

GCR General Description (2004)
What it is, what it tries to accomplish, and what are its advantages and disadvantages.

GCR and Neutrality (2002)
The role of GCR in helping assure that colors that are gray in RGB stay that way after conversion.

GCR and UCR (2001)
How do they differ, and when should we use them? A wide-ranging thread that also covers scanner training.

GCR: The Case for Heavy (2001)
A GATF representative and Dan Margulis spar over the amount of black to use.

GCR: Separating Cartoons and Other Linework (2000)
When the desired black contains black ink only, think Maximum GCR.

GCR: Separating to 4/c Grayscale (2004)
Discussion of when it is advisable to use less total ink in shadow areas.

Gravure and How to Prepare for It (2005)
What a gravure separation requires, and what to do if the printer doesn't communicate well.

How Harsh a Black? (2001)
Certain kinds of black generation create a very weird-looking channel. But if you can't see the harshness in print, does it matter?

Importing Grayscale Into PDF (2004)
Special care needs to be taken so that it won't separate into four colors.

Ink Out of Nowhere (2008)
What accounts for the appearance of ink on the printed page, where the operator has specified blank white space in RGB?

Ink Sequencing and Its Effects (2006)
What is the proper order in which to lay down the CMYK inks?

LAB Conversions and White Point (2004)
The white point used in converting out of LAB, and other separation issues.

Is Newspaper Production Quality Declining? (2012) 
The terrible economic conditions faced by modern American newspapers has cut maintenance and training budgets. What is the impact on us?

Newsprint and Color Settings (2000)
How to repurpose files originally prepared for reasonable printing conditions for much worse conditions.

Newsprint: Grayscale Images to Newspaper CMYK (2004)
GCR and dot gain settings to create optimal 4/c B/W images.

Newsprint: Preparing Files for Local Newspaper (2004)
What to do when the printing conditions are unclear.

Newsprint: Printing to a Grayscale (2000)
Should newspapers include a grayscale for quality control reasons?

Overseas Printing (2001)
Threads on how to prepare files for printing in Europe and Asia, assuming that very little is known about the specific conditions.

Pantone and CMYK Values (2005)
Why do different programs produce different CMYK breakouts for PMS colors?

Pantone Colors and RIPs (2006)
How does the RIP determine what CMYK breakout to use?

Printers Who Advocate Photoshop Defaults (2005)
If you ask the printer what Photoshop color settings to use and he replies with a listing of the Photoshop defaults, what does it imply?

Printing with Food Colorings (2003)
A requirement that the inks be edible makes for some unpalatable color.

Reverse Engineering Seps (2002)
The job comes out much darker than expected. Did the printer sabotage it? Whithout having access to the original files on which the assumptions were based, is there any way to figure out what went wrong? A lengthy, entertaining, and instructive thread.

Rich Black (2000)
What's the best formula for backing up solid blacks with process inks?

Scum Dots and Conversions (2003)
Why certain algorithms cause areas of pure white in RGB to convert to something other than 0c0m0y.

Spot Colors and Ink Order (2004)
How the presence of a fifth color affects the order in which inks are printed.

SWOP Gray Balance (2005)
Why does the default Photoshop "SWOP" profile not use the same gray balance that SWOP itself does?

SWOP v.2=Exaggerated Blue (2004)
The default, uneditable Photoshop CMYK profile and how it deals with near-neutral blues.

SWOP v.2, Custom CMYK, and Blues (2005)
A lengthy and heated discussion of how blues go purple during separation.

SWOP v.2 and Web v. Sheetfed Printing: How Many Jobs? (2003)
Photoshop's “Sheetfed” profile produces a darker separation than its “Web” profile, an impossible result. A lengthy thread discusses dot gain considerations.

SWOP v.2, Web and Sheetfed (2004)
A wide-ranging discussion comparing default and Custom CMYK profiles, what can be edited and what can't, and why it's hard to find good people nowadays.

Total Ink Limits (1999)
Discussion on total ink limits in shadows.

Total Ink Limit (2000)
When, why, and how much is too much.

Total Ink Limit: Converting 300% to 245% (2005)
List members discuss the best way to make the transition.

Total Ink: Photoshop Default Separations (2004)
Discussion of when it is advisable to use less total ink in shadow areas.

When Total Ink Limit Is Exceeded (2006-2007)
Recommended procedures for when CMYK files are encountered with illegally high inking values.

Total Ink: How to Check (2007)
Is there an easy way to check large quantities of images for violation of an ink limit?

The TR001 Standard and Proofing (2003)
List members ask whether the TR001 standard is sufficient to make a proper separation.

Traditional Process Camera Separations (2005)
How was the black channel generated?

Two-Color Spot Files (2004)
Members discuss how to make a 2/c Pantone color file separate from within a Quark file.

Why Do Printers Convert CMYK Files? (2005)
Some of the factors that may motivate a printer to alter a client's supplied CMYK file.

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