Layer Management

Layers are the foundation of non-destructive editing. They allow you to stack, organize, and independently edit different elements of your composition.

Understanding Layers

Think of layers as transparent sheets stacked on top of each other. Each layer can contain an image, text, solid color, or painted content. You can rearrange, show/hide, and adjust each layer independently without affecting others.

Layer Types

Basic Layer Operations

Adding Layers

• Import image: Drag & drop or use file upload — each image becomes a new layer
• Add text: Press T or use the Text tool to create a text layer
• Add paint canvas: Use Drawing Tools to create a new paint layer
• Duplicate: Ctrl/Cmd + J duplicates the active layer

Selecting Layers

• Click a layer in the Layers panel (Dock area) to select it
• Click directly on a layer element in the canvas viewport

Reordering Layers

• Drag layers up/down in the Layers panel to change their stacking order
• Layers at the top of the list appear in front

Hiding/Showing Layers

• Click the visibility icon (👁️) next to a layer to toggle its visibility
• Hidden layers are preserved but not rendered

Deleting Layers

• Select a layer and press Delete/Backspace, or use the delete button in the Layers panel

Layer Properties

Quick Opacity via Number Keys

Press number keys 1–0 to set the active layer's opacity in 10% increments:

• 1 = 10%, 2 = 20%, ... 9 = 90%, 0 = 100%

Transform Operations

With a layer selected:

• Move: Drag the layer on canvas
• Scale: Drag corner handles for proportional scaling; drag edge handles to scale one axis only

Note: Rotation and flipping are applied at the canvas/viewport level (90° increments) via the Viewport options buttons in the Option Bar, not on individual layers.

Blend Modes (16)

Blend modes control how each layer's pixels combine with the layers below:

Common Recipes

• Add texture: Place texture on top → set to Overlay or Soft Light → reduce opacity to 20-60%
• Brighten a dark photo: Duplicate layer → set to Screen → adjust opacity
• Color tint: Add solid Color layer → set to Color or Soft Light → choose tint color

Merge Layers

• Merge Down: Combines the active layer with the one below it
• Merge Visible: Merges all visible layers into a single layer

Channels Panel

The Layers panel includes a Channels tab that lets you view individual color channels of your image — useful for color correction, masking, and understanding image composition.

Available Channels

Interaction Model

• Eye toggle: Toggle channel visibility on/off. Disabled channels are zeroed out in the display (e.g., hide Red to see only Green + Blue)
• Row click: Solo a single channel as grayscale (useful for examining tonal detail in one channel)
• Alpha solo: Toggling Alpha ON automatically disables RGB — shows the transparency map as a grayscale image
• Reset: Toggle any RGB channel back ON to return to normal color viewing

Use Cases

• Spot color issues: View individual channels to find noise, banding, or compression artifacts
• Alpha inspection: Verify transparency masks and semi-transparent areas
• Channel-based selection: Identify which channel has the best contrast for making a selection

Non-Destructive Editing

OpenGPEX preserves your original image data at all times:

• Original assets are stored by content hash (SHA-256)
• Layer position, masks, and filters are just metadata
• Undo/Redo can restore any previous state without quality loss

Next Steps

• Color Adjustments — Fine-tune colors and tones
• Masks & Non-Destructive Editing — Hide/reveal parts of layers
• Selection & Clipping — Select specific regions

Last updated: 2026-07-30