Color Conversion

Convert RGB to CMYK with precision and control

Color Conversion Overview

Printery converts your RGB designs to CMYK for professional printing, using industry-standard ICC profiles for accurate color reproduction.

Why convert? Screens use RGB (light), printers use CMYK (ink). Conversion ensures your colors print as expected.

Accessing Color Conversion

1. Select Frame

   Click the frame you want to export

2. Launch Plugin

   Plugins → Printery

3. Color Tab

   Click “Color” tab in the plugin interface

4. Enable CMYK Conversion

   Toggle: “Convert to CMYK” ✓ ON

Key Color Settings

1. CMYK Conversion Toggle

Enabled (Recommended)

When ON:

• All RGB colors converted to CMYK
• Uses selected ICC profile
• PDF contains CMYK values
• Ready for professional printing

Result:

RGB (255, 0, 0) → CMYK (0, 100, 100, 0)
Screen red      → Print red

Use for: Professional printing

Disabled

When OFF:

• Colors stay RGB
• No conversion performed
• PDF contains RGB values
• Printer handles conversion (risky!)

Result:

RGB (255, 0, 0) → RGB (255, 0, 0)
Unknown CMYK result at printer

Use for: Digital-only output, screen viewing

2. ICC Profile Selection

Most important color decision!

ISO Coated v2 300%

Region: Europe, Global

Standard: ISO 12647-2

Paper: Coated (glossy/matte)

Ink Limit: 300% TAC

When to use:

• European printing
• Standard commercial projects
• Magazine/brochure production
• Default recommendation (works 90% of time)

Color characteristics:

• Vibrant colors
• Good gamut
• Industry standard

US Web Coated (SWOP) v2

Region: United States

Standard: SWOP

Paper: Coated web press

Ink Limit: 300% TAC

When to use:

• US printing
• Magazine/newspaper
• Web offset printing

Color characteristics:

• Slightly less vibrant than ISO
• Optimized for US standards
• Industry standard in USA

GRACoL 2006

Region: United States

Standard: GRACoL

Paper: Coated sheet-fed

Ink Limit: 300% TAC

When to use:

• US high-end printing
• Commercial sheet printing
• Premium quality work

Color characteristics:

• Excellent reproduction
• Tighter tolerances
• Premium quality

PSO Uncoated

Region: Europe

Paper: Uncoated offset

Ink Limit: 260% TAC

When to use:

• Letterhead
• Books (uncoated)
• Envelopes
• Natural paper

Color characteristics:

• More subdued
• Lower ink limit
• Organic look

Custom ICC

Pro Feature: Upload custom profile

When to use:

• Printer provides specific profile
• Specialty substrates
• Color-critical work
• Custom press setup

How to:

1. Get .icc file from printer
2. Click “Upload Custom Profile”
3. Select file
4. Appears in dropdown

See ICC Profiles Guide

3. Rendering Intent

How to handle out-of-gamut colors (colors that can’t be reproduced in CMYK)

Relative Colorimetric

Method: Shifts out-of-gamut colors to nearest CMYK equivalent

Characteristics:

• Maintains in-gamut colors exactly
• Clips out-of-gamut to gamut edge
• Preserves white point
• Most predictable

Best for:

• Logos (color accuracy)
• Brand colors
• Spot color simulation
• Default choice (90% of cases)

Example:

Bright RGB blue → Closest CMYK blue
(slightly less vibrant)

Perceptual

Method: Compresses entire color range to fit CMYK gamut

Characteristics:

• Maintains color relationships
• All colors shift proportionally
• No clipping
• Smoother gradients

Best for:

• Photographs
• Images with many colors
• Gradients
• When relationships matter more than accuracy

Example:

All colors shift slightly
But relationships preserved

Saturation

Method: Maximizes color vividness

Characteristics:

• Ignores accurate color matching
• Maximizes saturation
• Shifts colors significantly
• Vibrant output

Best for:

• Charts and graphs
• Presentations
• When impact > accuracy
• Bold designs

Rarely used for professional print

Absolute Colorimetric

Method: Exact color simulation, including paper white

Characteristics:

• Most accurate possible
• Simulates paper color
• No white point adaptation
• Used for proofing

Best for:

• Color proofing
• Simulating one printer on another
• Special applications

Almost never used for normal printing

Recommendation: Use Relative Colorimetric for 95% of projects

4. Black Generation Method

How CMYK black is created

GCR (Gray Component Replacement)

Method: Replaces CMY gray with K (black ink)

How it works:

Instead of: C50 M50 Y50 K0 (gray from colors)
Use: C10 M10 Y10 K70 (gray from black ink)

Characteristics:

• Lower total ink
• Faster drying
• Better neutrals
• Industry standard

Advantages:

• Reduced TAC
• Cleaner grays
• Better registration (less critical)
• Cost savings (less CMY ink)

Best for: Most modern printing

✅ Default recommendation

UCR (Under Color Removal)

Method: Removes CMY only in dark areas (shadows)

How it works:

• Neutral shadows use black
• Colors stay rich (more CMY)
• Traditional method

Characteristics:

• Richer colors
• Higher TAC
• More ink used
• Older standard

Advantages:

• Slightly richer colors
• Some printers prefer

Disadvantages:

• Higher ink coverage
• Longer drying
• More critical registration

Best for: Traditional presses, when requested

Maximum GCR

Method: Maximum black, minimum CMY

How it works:

• Replaces CMY with K wherever possible
• Very low total ink
• Aggressive black generation

Characteristics:

• Lowest TAC
• Fastest drying
• Less vibrant colors

Best for:

• Newspaper printing
• Low-quality paper
• Fast-turnaround work

Rarely used for quality printing

Recommendation: Use GCR (Medium) - the default ICC profile setting

5. Black Handling

How to treat black elements

Automatic

Smart black conversion:

• Text → Pure black (K100)
• Small elements → Pure black
• Large areas → Rich black

Settings:

• Text < 18pt: K100
• Lines < 2pt: K100
• Shapes > 1 inch²: Rich black (C60 M40 Y40 K100)

Result: Best of both worlds

✅ Recommended for most projects

All Pure Black

Everything becomes K100:

• Text: K100
• Shapes: K100
• Backgrounds: K100

Characteristics:

• Safest choice
• No registration issues
• Lighter black appearance

Best for:

• Text-heavy documents
• When registration is concern
• Desktop printing

Trade-off: Less dramatic black

All Rich Black

Everything uses rich black:

• Formula: C60 M40 Y40 K100

Characteristics:

• Deepest black
• Maximum impact
• Registration-sensitive

⚠️ Warning: NOT for text!

Best for: Large solid areas only

Risk: Text will blur

Custom Formula

Pro Feature: Specify rich black recipe

Options:

• Cyan: 0-100%
• Magenta: 0-100%
• Yellow: 0-100%
• Black: 90-100%

Example recipes:

• Cool: C60 M40 Y40 K100
• Warm: C40 M60 Y60 K100
• Neutral: C30 M30 Y30 K100

Check: Total TAC ≤ 300%

See Black Handling Guide

6. Spot Colors (Pro)

Add Pantone or special inks

Enable Spot Colors

Toggle: “Add Spot Colors” ✓

What it does:

• Converts specific colors to spot plates
• Adds Pantone to CMYK
• Creates separate ink plate

Use for:

• Brand colors (exact match)
• Colors outside CMYK gamut
• Metallic/fluorescent inks

Pro feature: Requires Pro subscription

Add Spot Color

Process:

1. Click “Add Spot Color”
2. Choose Pantone from library
3. Or enter Pantone number (e.g., “185 C”)
4. Map to RGB color in design

Example:

Design color: RGB (200, 16, 46)
Maps to: Pantone 185 C
PDF plate: Pantone 185 C (spot)

Spot Color Settings

Density: 0-100%

• 100% = Full strength (standard)
• 50% = Half tint
• Custom = Special effects

Overprint: Yes/No

• Yes = Prints over CMYK
• No = Knocks out background

Type:

• Coated (C) - Glossy paper
• Uncoated (U) - Matte paper

See Spot Colors Guide

Color Conversion Process

What Happens Behind the Scenes

1. 1. Color Detection

   Plugin scans your design:

   • All fills (shapes, text)
   • All strokes (borders, lines)
   • All images (raster graphics)
   • All effects (shadows, glows)

   Identifies: RGB, HEX, HSL values

2. 2. Profile Application

   ICC profile loaded:

   • Selected profile (e.g., ISO Coated v2)
   • Contains color space definition
   • Defines conversion rules

   Creates: RGB → CMYK lookup table

3. 3. Color Mapping

   Each color converted:

   • RGB value input
   • Profile lookup
   • CMYK value output

   Example:

   RGB (255, 0, 0)  [Red]
   ↓ (ISO Coated v2 profile)
   CMYK (0, 100, 100, 0)  [Red]
   
4. 4. Gamut Handling

   For out-of-gamut colors:

   • Rendering intent applies
   • Relative: Shift to nearest
   • Perceptual: Compress range
   • Saturation: Maximize vividness

   Result: All colors within CMYK gamut

5. 5. Black Generation

   For neutral/dark colors:

   • GCR or UCR applied
   • CMY replaced with K where appropriate
   • TAC reduced

   Example:

   C50 M50 Y50 K0  (240% TAC)
   ↓ (GCR applied)
   C10 M10 Y10 K70  (100% TAC)
   
6. 6. Special Handling

   Black elements:

   • Automatic detection
   • Text → K100
   • Large shapes → Rich black

   Spot colors (if enabled):

   • Mapped colors → Pantone
   • Separate plates created
7. 7. PDF Generation

   Final output:

   • All colors now CMYK
   • ICC profile embedded
   • Spot color plates (if used)
   • Color space: DeviceCMYK

Gamut Mapping

Understanding CMYK Gamut

RGB vs CMYK color range:

RGB Gamut (Screen):
 ┌────────────────────┐
 │   Wider range      │
 │  ┌──────────────┐  │
 │  │ CMYK Gamut   │  │ Some RGB colors
 │  │ (Printable)  │  │ can't be printed
 │  └──────────────┘  │
 └────────────────────┘

Problem areas:

• Bright blues: RGB brighter than CMYK
• Vivid greens: RGB more saturated
• Neon colors: Impossible in CMYK
• Bright oranges/reds: Slight shift

Out-of-Gamut Warning

Plugin shows warnings:

⚠️ 15 colors out of gamut

These RGB colors cannot be accurately reproduced in CMYK:

• Bright blue (#00FFFF) - will be duller
• Neon green (#00FF00) - will be less vibrant
• …

Preview shows closest CMYK match

Options:

1. Accept conversion - Use closest CMYK match
2. Adjust design - Use CMYK-friendly colors
3. Use spot colors - Add Pantone for critical hues

TAC (Total Area Coverage)

TAC Limits by Profile

Plugin enforces TAC limits:

Profile	TAC Limit
ISO Coated v2	300%
FOGRA39	300%
SWOP	300%
GRACoL	300%
PSO Uncoated	260%
Japan Color	350%

TAC Calculation

Formula:

TAC = C% + M% + Y% + K%

Examples:

✓ C60 + M40 + Y40 + K100 = 240% (OK for 300% limit)
✓ C30 + M30 + Y30 + K100 = 190% (OK)
✗ C100 + M100 + Y100 + K100 = 400% (EXCEEDS 300%)

Automatic TAC Control

Plugin automatically:

• Calculates TAC for all colors
• Reduces if exceeds limit
• Applies GCR to lower total
• Ensures compliance

What you see:

Before: C80 M80 Y80 K50 (290% TAC) ✓
After GCR: C40 M40 Y40 K90 (210% TAC) ✓

Color Accuracy

Factors Affecting Accuracy

Factor	Impact	Your Control
ICC Profile choice	High	✓ Select correct profile
Rendering intent	Medium	✓ Choose intent
Source colors	High	✓ Design CMYK-friendly
Printer calibration	High	✗ Printer’s responsibility
Paper type	Medium	✓ Specify coated/uncoated
Monitor calibration	High	✓ Calibrate if possible

Improving Color Accuracy

1. 1. Ask Your Printer

   Get specifications:

   • Preferred ICC profile
   • TAC limit
   • Paper type
   • Special requirements

   Why: Eliminates guesswork

2. 2. Use Correct Profile

   Match printer’s spec:

   • If US: SWOP or GRACoL
   • If Europe: ISO Coated v2
   • If custom: Upload their profile

   Impact: Biggest accuracy factor

3. 3. Order Physical Proof

   Before full run:

   • $10-50 test print
   • Actual paper and ink
   • Verify colors in person

   Adjust if needed, then proceed

4. 4. Design CMYK-Friendly

   Avoid problem colors:

   • Neon/fluorescent
   • Bright RGB blues
   • Extreme saturation

   Use: CMYK color picker when designing

Preview Before Converting

Soft Proofing

See CMYK preview before exporting:

1. Enable Soft Proof

   In plugin: “Preview CMYK Conversion” ✓

2. Side-by-Side Comparison

   View:

   • Left: Original RGB
   • Right: Converted CMYK

   Compare colors

3. Identify Issues

   Look for:

   • Major color shifts
   • Loss of vibrance
   • Unexpected changes
4. Adjust if Needed

   • Change design colors
   • Try different profile
   • Add spot colors
   • Accept trade-offs

Troubleshooting Color Conversion

Colors look dull after conversion

Cause: RGB gamut larger than CMYK

Normal: Some shift expected

Solutions:

• Use CMYK-friendly colors in design
• Try Perceptual rendering intent
• Add spot colors for critical hues
• Order proof to verify

TAC exceeds limit error

Cause: Too much total ink

Plugin action: Automatically reduces

Manual fix:

• Enable GCR
• Reduce rich black formula
• Check dark colors

Verify: TAC ≤ profile limit

Black looks wrong (too light or too colorful)

Cause: Black handling setting

Solutions:

• Text: Set to Pure Black (K100)
• Backgrounds: Set to Rich Black
• Check automatic mode enabled

Printer says wrong color space

Cause: Incorrect ICC profile

Fix:

• Ask printer for profile name
• Select correct profile
• Re-export PDF
• Verify with printer

Color Conversion Checklist

Before exporting:

• CMYK conversion enabled: Toggle ON
• ICC profile selected: ISO Coated v2 or printer-specified
• Rendering intent: Relative Colorimetric (usually)
• Black generation: GCR enabled
• Black handling: Automatic (text=K100, shapes=rich)
• TAC compliance: ≤ 300% (or profile limit)
• Spot colors configured: If using Pantone
• Preview checked: Soft proof reviewed

Learn More

ICC Profiles Guide

Choose the right profile

RGB vs CMYK

Deep dive into color models

Black Handling

Pure vs rich black

Spot Colors

Pantone and special inks

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Pro Tip: 95% of projects work perfectly with: ISO Coated v2 + Relative Colorimetric + GCR + Automatic black handling!