# Master Slide

> Explore Aspose.Slides for .NET master slide examples: create, edit, and style masters, placeholders, and themes in PPT, PPTX, and ODP with clear C# code.

Source: https://docs.aspose.com/slides/net/examples/elements/master-slide/
Updated: 2026-08-05


Master slides form the top level of the slide inheritance hierarchy in PowerPoint. A **master slide** defines common design elements such as backgrounds, logos, and text formatting. **Layout slides** inherit from master slides, and **normal slides** inherit from layout slides.

This article demonstrates how to create, modify, and manage master slides using Aspose.Slides for .NET.

## **Add a Master Slide**

This example shows how to create a new master slide by cloning the default one. It then adds a company name banner to all slides through layout inheritance.

```csharp
using System.Drawing;
using Aspose.Slides;

static void AddMasterSlide()
{
    using var presentation = new Presentation();

    // Clone the default master slide.
    var defaultMasterSlide = presentation.Masters[0];
    var newMasterSlide = presentation.Masters.AddClone(defaultMasterSlide);

    // Add a banner with company name to the top of the master slide.
    var textBox = newMasterSlide.Shapes.AddAutoShape(ShapeType.Rectangle, x: 0, y: 0, width: 720, height: 25);
    textBox.TextFrame.Text = "Company Name";
    textBox.TextFrame.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.FillType = FillType.Solid;
    textBox.TextFrame.Paragraphs[0].ParagraphFormat.DefaultPortionFormat.FillFormat.SolidFillColor.Color = Color.Black;
    textBox.FillFormat.FillType = FillType.NoFill;

    // Assign the new master slide to a layout slide.
    var layoutSlide = presentation.LayoutSlides[0];
    layoutSlide.MasterSlide = newMasterSlide;

    // Assign the layout slide to the first slide in the presentation.
    presentation.Slides[0].LayoutSlide = layoutSlide;
}
```

> 💡 **Note 1:** Master slides provide a way to apply consistent branding or shared design elements across all slides. Any changes made to the master will automatically reflect on dependent layout and normal slides.

> 💡 **Note 2:** Any shapes or formatting added to a master slide are inherited by layout slides and, in turn, all normal slides using those layouts.
> The image below illustrates how a text box added on a master slide is automatically rendered on the final slide.

![Master Inheritance Example](master-slide-banner.png)

## **Access a Master Slide**

You can access master slides using the `Presentation.Masters` collection. Here’s how to retrieve and work with them:

```csharp
using Aspose.Slides;

static void AccessMasterSlide()
{
    using var presentation = new Presentation();

    // Access the first master slide.
    var firstMasterSlide = presentation.Masters[0];

    // Change the background type.
    firstMasterSlide.Background.Type = BackgroundType.OwnBackground;
}
```

## **Remove a Master Slide**

Master slides can be removed either by index or by reference.

```csharp
using Aspose.Slides;

static void RemoveMasterSlide()
{
    using var presentation = new Presentation("sample.pptx");

    // Remove a master slide by index.
    presentation.Masters.RemoveAt(0);

    // Remove a master slide by reference.
    var firstMasterSlide = presentation.Masters[0];
    presentation.Masters.Remove(firstMasterSlide);
}
```

## **Remove Unused Master Slides**

Some presentations contain master slides that are not in use. Removing these slides can help reduce file size.

```csharp
using Aspose.Slides;

static void RemoveUnusedMasterSlide()
{
    using var presentation = new Presentation();

    // Remove all unused master slides (even those marked as Preserve).
    presentation.Masters.RemoveUnused(ignorePreserveField: true);
}
```



## Related articles

- [Layout Slide](https://docs.aspose.com/slides/net/examples/elements/layout-slide/)
- [Manage Presentation Slide Masters in .NET](https://docs.aspose.com/slides/net/slide-master/)