How to Shrink Selection from Image Border in GIMP

This guide explains how to use GIMP's Shrink Selection tool specifically with the "Shrink from image border" option enabled. In GIMP, shrinking a selection normally keeps the edges anchored if the selection touches the canvas boundary. By using the "Shrink from image border" setting, you force the selection to contract away from the canvas edges, making it ideal for creating uniform borders, frames, and inner margins.

What the "Shrink from image border" Option Does

By default, when you have an active selection that touches the edge of your canvas (such as after pressing Ctrl + A to select the entire image) and apply the standard Shrink command, GIMP keeps the selection glued to the image boundaries and only contracts edges that are inside the canvas. Checking the Shrink from image border option overrides this behavior, treating the canvas boundary as an edge to shrink away from.

Step-by-Step Instructions

  1. Create an Active Selection: Open your project in GIMP. Create a selection using any selection tool (such as the Rectangle Select Tool), or press Ctrl + A (Windows/Linux) or Cmd + A (macOS) to select the entire canvas.

  2. Open the Shrink Selection Dialog: In the top menu, navigate to Select > Shrink....

  3. Set the Shrink Distance: In the dialog box that appears, enter the number of pixels (or change the unit dropdown to inches, millimeters, or percent) by which you want to reduce the selection.

  4. Enable "Shrink from image border": Check the box next to Shrink from image border. If this box remains unchecked, any part of the selection touching the outer boundary of the canvas will not move inward.

  5. Apply the Changes: Click OK. The selection will immediately contract inward from all outer edges of the canvas by the specified distance.

Common Use Cases

  • Creating Inset Borders: Select all (Ctrl + A), shrink from the image border by your desired border width, invert the selection (Select > Invert), and fill it with a color or pattern.
  • Cropping Margins: Contract a full-image selection away from the borders and navigate to Image > Crop to Selection to trim an equal amount from all sides of the image.