MYLPER

Layers, groups and masks

Updated 2026-10-09

A document is a stack of layers. Layers higher in the Layers panel cover the ones below them. Every change can be undone.

Kinds of layers

  • Pixel layers — images and painting. Layer → New Layer adds an empty one.
  • Shape layers — rectangles, ellipses and lines that stay editable.
  • Text layers — text you type on the canvas and can edit any time.
  • Fill layers — a solid colour covering the canvas.
  • Adjustment layers — Levels, Curves, Brightness/Contrast, Hue/Saturation, Vibrance, Color Balance, Photo Filter, Channel Mixer, Gradient Map, Exposure, Temperature/Tint, Black & White, Invert, Posterize and Threshold. They change everything below them without touching the pixels. A new Gradient Map runs from the foreground to the background colour; add up to 16 colour stops in the Properties panel.

Levels and Curves

Adjustments → Levels sets the black point, white point and midtones (gamma) of the image below, and can compress the output range. Adjustments → Curves gives full control of the tones: click the curve to add a point, drag it, and drag a point off the graph to remove it. A point can also be moved with the arrow keys (Shift for steps of 10), or by typing its input and output values. Both work on the combined RGB channel or on red, green and blue separately, and show a histogram of the image beneath the layer.

Opacity and blend modes

Each layer has an opacity and one of 16 blend modes (Multiply, Screen, Overlay and more) in the Properties panel.

Groups

Select layers and press Cmd/Ctrl+G to put them in a group; Cmd/Ctrl+Shift+G ungroups. Drag layers in the Layers panel to reorder them or move them into a group. By default a group passes its layers' blending through; give it opacity, a blend mode, a mask or effects to treat it as one unit. With the Move tool, a selected group shows a frame: drag it to move the group, drag its handles to scale everything inside, or drag just outside a corner to rotate it.

Selecting several layers

  • In the Layers panel, Cmd-click (Ctrl-click on Windows) adds or removes a layer; Shift-click selects every layer between the active one and the one you click. Select → All Layers (Cmd/Ctrl+Alt+A) selects everything.
  • With the Move tool and Auto-select on, Shift-click a layer on the canvas to add it.
  • Selected layers move, scale, rotate and flip together, and can be grouped, duplicated or deleted in one step. The Properties panel shows the settings of the active layer (the one you selected last).
  • Painting, filters and adjustments still work on the active layer only.

Align and distribute

Layer → Align lines up the selected layers with each other — or with the pixel selection, if there is one. A single layer aligns to the canvas. Layer → Distribute spaces three or more layers evenly, by their centres or with equal gaps between them; the outermost layers stay where they are. The same buttons are in the Move tool's options bar and the Properties panel when several layers are selected.

Masks

Layer → Add Layer Mask hides parts of a layer without erasing them. Click the mask thumbnail, then paint black to hide, white to reveal and grey for partial transparency. Shift-click the thumbnail to turn the mask off temporarily. With a selection active, the new mask reveals only the selection.

Clipping masks

Layer → Create Clipping Mask (Cmd/Ctrl+Alt+G) shows a layer only where the layer directly below it has pixels — for example a photo inside a text or shape. Clipped layers are indented with ↳ in the Layers panel and the layer they clip to is underlined. Several layers can clip to the same base, and a clipped adjustment layer changes only that base.

Vector masks

A vector mask hides a layer outside a path, with perfectly smooth edges at any size. Draw a path with the Pen tool in Path mode, then choose Layer → Add Vector Mask from Path (or the Mask button in the Pen options). Edit its points with the Direct Selection tool (A); Shift-click the mask badge in the Layers panel to turn it off. A layer can have both a pixel mask and a vector mask. See paths and the Pen tool.

Effects

Drop shadow, outer glow, inner shadow, bevel, gradient overlay, outer stroke and colour overlay are in the Properties panel. Layers with effects show an fx badge. The gradient overlay spans the layer's box (a new pixel layer is as big as the canvas); the bevel is a soft inner bevel made from a highlight and a shadow along the edges.

Limitations

  • Masks follow a layer when it moves, but not when it is scaled or rotated.
  • Stretching a selection that contains rotated layers keeps each of those layers rectangular (MYLPER has no skew): their centres move correctly, but their shape is not sheared.
  • Clipped layers are limited to the base layer's pixels; on semi-transparent base pixels the result can differ slightly from Photoshop.