> ## Documentation Index
> Fetch the complete documentation index at: https://docs.printery.app/llms.txt
> Use this file to discover all available pages before exploring further.

# RGB vs CMYK Deep Dive

> Complete technical guide to understanding RGB and CMYK color models

## The Fundamental Difference

RGB and CMYK are opposite color models:

| Aspect       | RGB                      | CMYK                             |
| ------------ | ------------------------ | -------------------------------- |
| **Method**   | Additive (adds light)    | Subtractive (absorbs light)      |
| **Medium**   | Light emission           | Ink on paper                     |
| **Black**    | Absence of light (0,0,0) | All inks mixed                   |
| **White**    | All light (255,255,255)  | No ink (paper white)             |
| **Channels** | 3 (Red, Green, Blue)     | 4 (Cyan, Magenta, Yellow, Black) |
| **Gamut**    | Wider (more colors)      | Narrower (fewer colors)          |
| **Use**      | Screens, digital         | Physical printing                |

<Note>
  **Key Insight**: RGB creates color by adding light. CMYK creates color by subtracting (absorbing) light from white paper.
</Note>

## How RGB Works (Additive Color)

RGB is based on **light emission**:

```
Start with darkness (black)
+ Red light
+ Green light
+ Blue light
= White light
```

### RGB Color Mixing

* **Red + Green** = Yellow
* **Red + Blue** = Magenta
* **Green + Blue** = Cyan
* **All three** = White
* **None** = Black

### RGB Value Ranges

Each channel: **0-255** (256 levels)

* Total combinations: **16,777,216 colors**
* Example: `rgb(255, 0, 0)` = Pure red

### RGB Color Spaces

| Space            | Gamut Size          | Use Case             |
| ---------------- | ------------------- | -------------------- |
| **sRGB**         | Standard (smallest) | Web, general use     |
| **Adobe RGB**    | Wider               | Professional photo   |
| **ProPhoto RGB** | Widest              | High-end photography |
| **Display P3**   | Wide                | Apple devices        |

## How CMYK Works (Subtractive Color)

CMYK is based on **ink absorption**:

```
Start with white paper
+ Cyan ink (absorbs red, reflects blue+green)
+ Magenta ink (absorbs green, reflects red+blue)
+ Yellow ink (absorbs blue, reflects red+green)
+ Black ink (absorbs all light)
= Desired color
```

### CMYK Color Mixing

* **Cyan + Magenta** = Blue
* **Cyan + Yellow** = Green
* **Magenta + Yellow** = Red
* **C+M+Y** = Muddy brown (not true black)
* **Add K (Black)** = Clean blacks and shadows

### CMYK Value Ranges

Each channel: **0-100%**

* C50 M0 Y100 K0 = Lime green
* C100 M100 Y0 K0 = Blue
* C0 M0 Y0 K100 = Black

### Why "K" for Black?

Three theories:

1. **Key plate** - carries the key image details
2. **blacK** - distinguish from Blue (B)
3. **Keyline** - black outline in registration

<Info>
  Most likely: "K" = **Key plate** in traditional four-color printing.
</Info>

## The Gamut Gap

Not all RGB colors can be printed in CMYK:

```
Visible Spectrum
┌─────────────────────────────┐
│ RGB Gamut                   │
│ ┌────────────────────┐      │
│ │ CMYK Gamut         │      │
│ │ ┌──────────┐       │      │
│ │ │ Common   │       │      │
│ │ │ Colors   │       │      │
│ │ └──────────┘       │      │
│ └────────────────────┘      │
└─────────────────────────────┘

Overlap = Colors that exist in both
RGB only = Screen colors that can't print
CMYK only = Very rare (some dark browns)
```

### Out-of-Gamut Colors

**Most problematic RGB colors**:

* Bright neon blues (electric blue)
* Pure cyan (#00FFFF)
* Lime green (#00FF00)
* Pure magenta (#FF00FF)
* Bright orange (#FF6600)

These colors **will shift** when converted to CMYK - it's unavoidable.

## Conversion Process

### How Conversion Works

<Steps>
  <Step title="1. Analyze RGB Values">
    Plugin reads RGB color: e.g., rgb(0, 128, 255)
  </Step>

  <Step title="2. Apply ICC Profile">
    Uses selected profile (e.g., ISO Coated v2) as conversion rules
  </Step>

  <Step title="3. Map to CMYK">
    Calculates closest CMYK equivalent
  </Step>

  <Step title="4. Apply Rendering Intent">
    Handles out-of-gamut colors based on intent selected
  </Step>

  <Step title="5. Check Ink Limits">
    Ensures total ink coverage doesn't exceed 300%
  </Step>

  <Step title="6. Embed in PDF">
    Creates CMYK PDF with embedded profile
  </Step>
</Steps>

### Color Conversion Examples

<Tabs>
  <Tab title="Example 1: Red">
    **RGB**: `rgb(255, 0, 0)` - Pure red
    **CMYK**: `C0 M100 Y100 K0`
    **Result**: ✅ Converts well (in both gamuts)
  </Tab>

  <Tab title="Example 2: Blue">
    **RGB**: `rgb(0, 100, 255)` - Bright blue
    **CMYK**: `C76 M50 Y0 K0` (approximately)
    **Result**: ⚠️ Slightly darker in print
  </Tab>

  <Tab title="Example 3: Green">
    **RGB**: `rgb(0, 255, 0)` - Lime green
    **CMYK**: `C70 M0 Y100 K0` (varies)
    **Result**: ❌ Significantly less vibrant
  </Tab>

  <Tab title="Example 4: Gray">
    **RGB**: `rgb(128, 128, 128)` - 50% gray
    **CMYK**: `C0 M0 Y0 K50`
    **Result**: ✅ Converts perfectly
  </Tab>
</Tabs>

## When to Use Which

### Use RGB When:

✅ **Designing for screens** - Websites, apps, presentations
✅ **Initial design phase** - Native Figma color space
✅ **Digital-only deliverables** - No physical printing
✅ **Video/motion graphics** - Screen-based media

### Use CMYK When:

✅ **Printing physically** - Anything on paper or substrate
✅ **Final print files** - Pre-press and production
✅ **Color-critical prints** - When accuracy matters
✅ **Communicating with printers** - Industry standard

<Warning>
  **Never design in CMYK in Figma!** Always design in RGB and convert for export. This gives you the most flexibility and compatibility.
</Warning>

## Black Handling: K vs CMY

Two ways to create black in CMYK:

### 1. Pure Black (K100)

* **Value**: C0 M0 Y0 K100
* **Ink**: Only black ink
* **Uses**: Body text, small type, thin lines
* **Pros**: Crisp, no registration issues, saves ink

### 2. Rich Black (4-Color Black)

* **Value**: C40 M30 Y30 K100 (typical recipe)
* **Ink**: All four inks
* **Uses**: Large black areas, backgrounds, headlines
* **Pros**: Deeper, richer black appearance

```
Pure Black (K100):
Adequate for text

Rich Black (C40 M30 Y30 K100):
Luxurious, deep, intense
```

<Tip>
  **Rule of Thumb**: Use K100 for text under 24pt. Use rich black for large areas.
</Tip>

## Total Ink Coverage (TAC)

**TAC** = Total Area Coverage - the sum of all four CMYK percentages

### Why It Matters

* Too much ink = Smearing, drying problems, paper saturation
* Most printers limit TAC to **280-320%**

### Example Calculation

```
Color: C80 M70 Y60 K40
TAC = 80 + 70 + 60 + 40 = 250%
✅ Within safe limits (under 300%)

Color: C100 M100 Y100 K100
TAC = 100 + 100 + 100 + 100 = 400%
❌ Too much! Will cause problems
```

<Warning>
  Printery automatically manages TAC based on your selected ICC profile. You don't need to calculate manually, but understanding helps!
</Warning>

## Color Management Strategies

### Strategy 1: Design CMYK-Friendly

**Approach**: Choose colors that exist in both gamuts

**How**:

* Avoid neon/fluorescent colors
* Test colors in CMYK preview
* Use CMYK color picker if available

**Pros**: Minimal color shift
**Cons**: Limits creative palette

***

### Strategy 2: Design Freely, Convert Carefully

**Approach**: Design in RGB, carefully manage conversion

**How**:

* Design with any colors
* Use high-quality ICC profiles
* Preview before finalizing
* Adjust problem colors manually

**Pros**: Full creative freedom
**Cons**: Requires color management knowledge

***

### Strategy 3: Hybrid (Spot Colors)

**Approach**: CMYK for most, spot colors for critical hues

**How**:

* Use CMYK for photos and most graphics
* Add Pantone spot colors for logos and brand colors
* Combine in same document

**Pros**: Best of both worlds
**Cons**: More expensive printing (extra plates)

## Previewing CMYK Conversion

How to see how colors will print:

### In Printery

<Steps>
  <Step title="Enable CMYK">
    Color tab → Convert to CMYK ✓
  </Step>

  <Step title="Select ICC Profile">
    Choose appropriate profile for your printing
  </Step>

  <Step title="Preview">
    Plugin shows color conversion preview
  </Step>

  <Step title="Adjust">
    If colors shift too much, adjust RGB values or use spot colors
  </Step>
</Steps>

### In Adobe Acrobat

After exporting:

1. Open PDF in Acrobat
2. Tools → Print Production → Output Preview
3. Enable CMYK simulation
4. See how colors will actually print

## Common Misconceptions

### Myth 1: "CMYK is always better for print"

**Reality**: Design in RGB (Figma's native), convert to CMYK for export. Best of both worlds.

***

### Myth 2: "My screen can show CMYK accurately"

**Reality**: Your screen is RGB. It can only *simulate* CMYK. Physical proofs are the only true preview.

***

### Myth 3: "If it looks good in RGB, it'll print fine"

**Reality**: Some RGB colors can't be reproduced in CMYK. Always preview conversion.

***

### Myth 4: "CMYK files are smaller"

**Reality**: CMYK files are usually *larger* (4 channels vs 3).

## Advanced: GCR vs UCR

Two methods for generating black (K) channel:

### GCR (Gray Component Replacement)

* Replaces CMY gray with K where possible
* Creates lighter, more stable print
* **Recommended for most projects**
* Less ink usage

### UCR (Under Color Removal)

* Only removes CMY under black areas
* Darker shadows
* More traditional method
* Used for specific effects

<Info>
  Printery uses **GCR** by default with ICC profiles - the modern standard for professional printing.
</Info>

## Quick Reference

| Factor           | RGB          | CMYK                 |
| ---------------- | ------------ | -------------------- |
| **Model**        | Additive     | Subtractive          |
| **Channels**     | 3            | 4                    |
| **Max Values**   | 0-255 each   | 0-100% each          |
| **Total Colors** | 16.7 million | \~Thousands (varies) |
| **Black**        | 0,0,0        | 0,0,0,100            |
| **White**        | 255,255,255  | 0,0,0,0              |
| **Use**          | Screen       | Print                |
| **Gamut**        | Wider        | Narrower             |

## Next Steps

<CardGroup cols={2}>
  <Card title="ICC Profiles Explained" icon="palette" href="/color/icc-profiles">
    Master ICC profile selection
  </Card>

  <Card title="Spot Colors Guide" icon="stamp" href="/color/spot-colors">
    When to use Pantone colors
  </Card>

  <Card title="Black Handling" icon="fill" href="/color/black-handling">
    Pure black vs rich black strategies
  </Card>

  <Card title="Color Troubleshooting" icon="wrench" href="/troubleshooting/color-issues">
    Fix common color problems
  </Card>
</CardGroup>

***

<Info>
  **Deep dive into color science?** Our [Discord community](https://discord.gg/kUJZQEfdUF) has color experts who love discussing this stuff!
</Info>