Colour Management

Total ink (C+M+Y+K) must stay below a limit set for the paper and printing method. The producer and selected preflight profile define the limit. A paper name alone is insufficient: check the printing method, profile and measurement coverage. Unmeasured TAC is not assumed below the limit.

A guide to CMYK, RGB, and colour profiles for colour accuracy in professional print.

Colour Modes

RGB (Red, Green, Blue)

Use Cases:

Screen display
Web design
Digital media
Video

Characteristic: Light-based (additive). RGB combined produces white.

CMYK (Cyan, Magenta, Yellow, Key/Black)

Use Cases:

Offset print
Digital print
Print shop jobs

Characteristic: Ink-based (subtractive). CMYK combined produces black.

RGB vs CMYK Comparison

Characteristic	RGB	CMYK
Gamut	Depends on RGB profile and bit depth	Depends on inks, paper and ICC profile
Vibrancy	Very vibrant	Less vibrant
Neon colours	Possible	Difficult
Print compatibility	Depends on profile and producer RIP plan	Depends on profile and producer RIP plan

Colour Shift

Transitioning from RGB to Print

Out-of-gamut colours may change when converting RGB to CMYK. These are illustrative shifts; the actual result depends on source/destination ICC profiles and rendering intent:

RGB Colour	CMYK Equivalent	Difference
Neon Green	Dark Green	Noticeable
Bright Blue	Flat Blue	Moderate
Orange	Similar	Minor

RGB acceptance depends on the selected profile and a verified producer RIP plan. NowToPrint does not perform general RGB/spot → CMYK conversion. Prepare any required conversion in the source application using the correct destination ICC profile; a CMYK label alone does not guarantee correct output.

Colour Profiles (ICC)

Common Profiles

Profile	Usage
ISO Coated v2	European coated paper
FOGRA39	European standard
US Web Coated (SWOP)	US standard
Japan Color 2001	Japanese standard

Profile Selection

Choose the destination ICC profile for the producer's printing condition. ISO Coated v2/FOGRA39 are historical coated-offset examples, not a universal NowToPrint default. Confirm that the output intent matches the actual printing condition.

Colour Consistency

Monitor Calibration

Calibrate your monitor for accurate colour display:

Use a professional calibrator
Calibrate brightness for the viewing conditions (for example, approximately 120 cd/m²)
Colour temperature: 6500K

Soft Proofing

For a print preview:

In your design software: View → Proof Colors
Select the CMYK profile
Review the colour differences

Problematic Colours

Colours That Are Difficult to Print

Colour	Problem	Solution
Neon/Fluorescent	Not available in CMYK	Spot colour or alternative
Metallic	Needs a special material, ink or effect	Confirm the material and proof plan with the producer
Very dark blue	Dark detail may be lost	Check tonal separation in the destination profile and proof

Total Ink Limit

The CMYK total (C+M+Y+K) must not exceed the specified limit:

Example totals (admission depends on the profile limit and measurement evidence):

C:100 + M:100 + Y:100 + K:100 = 400% — high total; compare with the profile limit
C:80 + M:80 + Y:80 + K:50 = 290% — not automatically acceptable

Spot Colours

Pantone (PMS)

Specially formulated inks:

A consistency target under controlled production; paper and printing conditions affect the result
Wide colour gamut
Metallic and neon options available
Additional cost

When to Use Them

Logo printing (brand consistency)
Corporate colours
Special effects (gold, silver)

Colour Verification

Preview

NowToPrint previews and render evidence support visual inspection; a screen image is not a contract colour proof or a RIP-equivalence guarantee.

Inspect the profile, output intent and measured coverage.
For critical brand colours, request a physical proof or approved colour evidence from the producer.

Colour Bar

In professional print, colour bars are added alongside crop marks for colour verification.

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