a:pattFill (Pattern Fill)

Description

\:pattFill\ is the DrawingML pattern fill element that applies a repeating geometric pattern to shapes, lines, and grouped shapes. It is defined in ECMA-376 Part 1 §20.1.4.7.

Pattern fills create distinctive textured appearances using predefined geometric patterns. Each pattern consists of:

• Foreground Color (\:fgClr): Color of the pattern elements (lines, dots, crosses)
• Background Color (\:bgClr): Color filling the space between pattern elements
• Pattern Type (prst attribute): Predefined geometric shape (horizontal lines, diagonal hatches, polka dots, etc.)

Pattern fills are valuable for:

• Creating distinctive hatch patterns in diagrams and charts
• Distinguishing areas without relying solely on color variation
• Improving accessibility for colorblind users (pattern + color combination)
• Creating texture effects for professional, polished documents
• Providing print-friendly alternatives to gradients
• Creating vintage or retro design effects

Pattern fills are lighter weight than gradients and render consistently across all Office applications.

Attributes

Content Model

\:pattFill\ contains exactly:

1. One foreground color element (\:fgClr)
2. One background color element (\:bgClr)

Pattern type specified via \prst\ attribute; no pattern child element.

Child Elements Table

Examples

Light Horizontal Lines Pattern

<a:spPr>
  <a:pattFill prst=\"ltHorz\">
    <a:fgClr>
      <a:srgbClr val=\"0070C0\"/>
    </a:fgClr>
    <a:bgClr>
      <a:srgbClr val=\"FFFFFF\"/>
    </a:bgClr>
  </a:pattFill>
</a:spPr>

using DocumentFormat.OpenXml.Drawing;

var spPr = new ShapeProperties();
var pattFill = new PatternFillProperties { Pattern = PatternValues.LightHorizontal };

var fgClr = new ForegroundColor();
fgClr.Append(new RgbColorModelHex { Val = \"0070C0\" });
pattFill.Append(fgClr);

var bgClr = new BackgroundColor();
bgClr.Append(new RgbColorModelHex { Val = \"FFFFFF\" });
pattFill.Append(bgClr);

spPr.Append(pattFill);

Diagonal Crosshatch Pattern

<a:pattFill prst=\"wdUpDiag\">
  <a:fgClr>
    <a:srgbClr val=\"FF0000\"/>
  </a:fgClr>
  <a:bgClr>
    <a:srgbClr val=\"FFFF00\"/>
  </a:bgClr>
</a:pattFill>

var pattFill = new PatternFillProperties { Pattern = PatternValues.WideUpwardDiagonal };

var fgClr = new ForegroundColor();
fgClr.Append(new RgbColorModelHex { Val = \"FF0000\" });
pattFill.Append(fgClr);

var bgClr = new BackgroundColor();
bgClr.Append(new RgbColorModelHex { Val = \"FFFF00\" });
pattFill.Append(bgClr);

Dark Vertical Lines with Scheme Colors

<a:pattFill prst=\"dkVert\">
  <a:fgClr>
    <a:schemeClr val=\"accent1\"/>
  </a:fgClr>
  <a:bgClr>
    <a:schemeClr val=\"lt1\"/>
  </a:bgClr>
</a:pattFill>

var pattFill = new PatternFillProperties { Pattern = PatternValues.DarkVertical };

var fgClr = new ForegroundColor();
fgClr.Append(new SchemeColor { Val = ColorSchemeIndexValues.Accent1 });
pattFill.Append(fgClr);

var bgClr = new BackgroundColor();
bgClr.Append(new SchemeColor { Val = ColorSchemeIndexValues.Light1 });
pattFill.Append(bgClr);

Small Confetti Pattern (Random dots)

<a:pattFill prst=\"smConfetti\">
  <a:fgClr>
    <a:srgbClr val=\"4472C4\">
      <a:alpha val=\"80000\"/>
    </a:srgbClr>
  </a:fgClr>
  <a:bgClr>
    <a:srgbClr val=\"E7E6E6\"/>
  </a:bgClr>
</a:pattFill>

var pattFill = new PatternFillProperties { Pattern = PatternValues.SmallConfetti };

var fgClr = new ForegroundColor();
var fgColor = new RgbColorModelHex { Val = \"4472C4\" };
fgColor.Append(new Alpha { Val = 80000 });
fgClr.Append(fgColor);
pattFill.Append(fgClr);

var bgClr = new BackgroundColor();
bgClr.Append(new RgbColorModelHex { Val = \"E7E6E6\" });
pattFill.Append(bgClr);

Polka Dots (Checkerboard) Pattern

<a:pattFill prst=\"prcChecker\">
  <a:fgClr>
    <a:srgbClr val=\"000000\"/>
  </a:fgClr>
  <a:bgClr>
    <a:srgbClr val=\"FFFFFF\"/>
  </a:bgClr>
</a:pattFill>

var pattFill = new PatternFillProperties { Pattern = PatternValues.LargeCheckerBoard };

var fgClr = new ForegroundColor();
fgClr.Append(new RgbColorModelHex { Val = \"000000\" });
pattFill.Append(fgClr);

var bgClr = new BackgroundColor();
bgClr.Append(new RgbColorModelHex { Val = \"FFFFFF\" });
pattFill.Append(bgClr);

Reference Tables

Light Patterns (ltXxx)

Dark Patterns (dkXxx)

Wide Patterns (wdXxx)

Notes

Element Relationships

• Parents: Shape properties (\:spPr), group properties (\:grpSpPr), line properties (\:ln)
• Fill Priority: Only one fill type allowed per container; first defined fill is applied
• Children: Exactly two color elements required – foreground (\:fgClr) and background (\:bgClr)
• Pattern Type: Specified via \prst\ attribute, not as child element

Implementation Details

• Color Types: Foreground and background support all color types (RGB, scheme, system, HSL, etc.)
• Accessibility: Pattern + color combinations improve readability for colorblind users
• Print Rendering: Patterns render consistently in print, unlike gradients which may appear banded
• Theme Colors: Using scheme colors enables automatic theme switching across documents
• Performance: Pattern fills are lightweight and render quickly even in large documents
• Compatibility: All Office applications support standard patterns consistently
• Pattern Exhaustiveness: 48+ patterns available covering lines, grids, dots, chevrons, waves
• Foreground/Background Order: XML order matters – foreground before background
• Pattern Density: Light patterns (~25% coverage), dark (~75%), wide (~50%)