How to Create a Custom macOS Installer (DMG Design Guide)

A default macOS installer works, but it doesn’t look professional.

A custom-designed .dmg installer:

  • builds trust;
  • improves perceived quality;
  • makes your app feel premium.

What Makes a Good Installer

A polished DMG typically includes:

  • Custom background image;
  • App icon placement;
  • Applications folder shortcut;
  • Directional arrow;
  • Clean layout and spacing.

Step 1: Create a Background Image

Design your background in:

  • Figma;
  • Photoshop;
  • Illustrator.

Recommended size:

  • 1600 × 1000 pixels

Step 2: Place Key Elements

You’ll need to align:

  • App icon;
  • Applications folder;
  • Arrow indicator.

Precision matters, even small misalignment looks unprofessional.

Step 3: Configure Finder Layout

This involves:

  • icon size;
  • grid spacing;
  • window size;
  • background placement.

Normally done manually via Finder scripting or Terminal.

Step 4: Lock Layout

Once positioned:

  • fix icon positions;
  • set window properties;
  • prevent layout shifting.

The Problem

Manually doing this:

  • is fragile;
  • breaks easily;
  • requires repeated tweaking.

The Better Way

Tools like DMGKit let you:

  • visually design your installer
  • align elements with pixel precision
  • preview before export
  • export a ready-to-ship DMG

No Finder hacks required.

Conclusion

A custom installer is one of the easiest ways to make your app feel premium.

It takes minutes with the right tool, and dramatically improves first impressions.