Layers

A layer is a picture stacked on top of another picture. The layers panel lists them, topmost first, and what you see on the canvas is the whole stack looked at from above.

Everything else on this page is a way of controlling how one layer meets the one beneath it.

The layers panel showing a stack of layers above a photograph

The panel

Control	What it does
The eye	Hides the layer without deleting it
The name	Double-click to rename — do it, you will thank yourself later
Blend mode	How this layer combines with everything below
Opacity	How much of it you see at all
Lock	Protects the pixels, the transparency, or the position
The row of buttons along the bottom	Add, duplicate, group, mask, adjustment layer, delete

Select a layer by clicking its row. Most commands act on the selected layer, and getting the wrong one selected is the commonest reason for "nothing happened when I painted".

Stacking order

Drag a row up or down to move it. Higher in the list means nearer the viewer.

The same stack after two layers have been reordered

Order is not cosmetic. A layer only affects what is beneath it, so moving one up or down changes the result whenever opacity or a blend mode is involved.

Opacity

Opacity is how much of the layer reaches the eye, from 100% (all of it) to 0% (none).

100%	60%	30%	0%

Lowering opacity is the quickest way to make any effect subtler. Apply it at full strength on its own layer, then dial the layer back until it looks right — much easier than guessing the right strength in a dialog.

Blend modes

A blend mode is a rule for combining this layer with what is beneath. There are twenty of them, and the picker groups them by what they do.

The blend mode picker, open, listing the modes by group

Start with Normal: the upper layer covers the lower one according to its alpha, mask and opacity, without a special colour interaction. Other modes change how the colours combine.

Common starting points

Multiply darkens. Every colour is multiplied by the one beneath, so white becomes invisible and everything else darkens what it covers. Use it for shadows, for stains, and for putting ink or pencil artwork over paper.

A layer set to Multiply, darkening the picture beneath

Screen is the opposite: it lightens, and black becomes invisible. Use it for glows, for light leaks, for fire and for anything that emits rather than reflects.

A layer set to Screen, lightening the picture beneath

Overlay does both at once — it darkens the dark parts and lightens the light parts, so it adds contrast and keeps mid-grey unchanged. Use it for contrast and for tinting.

A layer set to Overlay, increasing contrast in the picture beneath

Luminosity keeps this layer's brightness and the lower layer's colour. It is the one that makes adjustment layers behave: a contrast adjustment set to Luminosity changes the tones without saturating the colours, which is almost always what you wanted.

A layer set to Luminosity, changing brightness while keeping the colour beneath

The rest, briefly

Mode	What it is for
Darken, Lighten	Chooses the lower or higher value separately in each colour channel; the result can combine channels from both inputs
Colour burn, Colour dodge	Stronger versions of Multiply and Screen, with more contrast
Soft light, Hard light	Gentler and harsher versions of Overlay
Difference, Exclusion	Subtracts one from the other — useful for comparing two versions of a picture
Hue, Saturation, Colour	Takes one property from this layer and the rest from below
Behind, Erase	Shows only where the layer below is transparent, or punches a hole through everything beneath
Linear dodge	Adds the two together — a brighter, harsher Screen, good for light and fire
Exclusive or	Keeps what one layer covers and the other does not; a compositing tool rather than a look

The brush and the other painting tools offer a longer list than this one, including the linear and vivid variants and a few that only make sense under a moving brush. Those are covered in Painting and retouching.

Try them by cycling the picker with a layer selected and watching the canvas. Reading about blend modes is much less useful than seeing one.

Darken	Lighten	Difference	Hue

Colour burn	Colour dodge	Soft light	Exclusion

Groups

A group is a folder of layers that behaves as one. Put the six layers making up a sky into a group and you can hide, move, fade or mask the whole sky at once.

Before grouping	After grouping	Collapsed

Hiding a group hides everything in it.

A hidden group, with its contents gone from the canvas

Isolated and pass-through

This is the one part of groups that surprises people, and it is worth understanding once.

A group can combine with the rest of the picture in two ways:

Pass-through — the layers inside blend with everything below the group, exactly as they would if the group were not there. The group is only an organisational convenience.
Isolated — the layers inside blend with each other first, and the finished result is then blended with what is below as a single image.

The difference shows the moment a layer inside the group uses a blend mode.

Pass-through	Isolated

Use isolated when a group is a self-contained thing — a composited object, a graded version of the picture — that should not leak its internal blending onto the rest. Use pass-through when the group is just tidying.

Clipping one layer to another

Select the upper layer and choose Layer ▸ Clip to layer below. A clipped layer only shows where the layer beneath provides coverage. It is the easy way to confine something to a shape you have already made.

Not clipped	Clipped

Texture on a letterform, a colour wash on a cut-out object, a glow that must not spill — all of them are a clipped layer.

A mask does a similar job with more control; clipping is faster when the shape already exists as a layer.

Merging and flattening

Command	What it does
Merge down	Combines the selected layer with the one beneath into a single layer
Merge visible	Combines everything currently visible into one
Flatten image	Combines everything into one layer and discards transparency

Before merging	After merging

All three are destructive: the separate layers are gone, and only undo brings them back. There is rarely a reason to flatten while you are still working — exporting to JPEG or PNG flattens a copy for you and leaves your document alone.

A flattened document, reduced to a single layer

Keeping layers when you save

Layered formats do not all preserve the same objects. Save in .mie while you work to keep editable text, live adjustment layers, masks and selection along with pixels. Undo history is not restored when you reopen the file. Save separate versions before destructive changes.

Opening and saving has the full table.

Adding and organizing content

Use Layer ▸ Add for these tasks:

Command	Use it when
Blank layer	Paint separately from the photograph
Duplicate of current layer	Try a pixel effect while preserving the original
From file...	Bring another picture into this document
From visible layers	Make a combined snapshot above the existing pieces
Layer via copy	Copy selected pixels into a new layer
Layer via cut	Move selected pixels to a new layer, removing them from the source

Select the layers that belong together and use Layer ▸ Group layers. Name the group for its purpose, such as “Caption” or “Sky”. Layer ▸ Ungroup separates its contents again. Open the group's blend controls to choose pass-through or isolated behaviour; a group that changes the appearance unexpectedly may be blending with content outside it.

Layer opacity and masks multiply coverage. For an opaque pixel, 50% opacity and a 50% mask give 25% coverage before other compositing factors. A blend mode chooses how colours interact; it is not a replacement for either coverage control. See Image basics.

Masks — hiding part of a layer without deleting it
Adjustment layers — corrections that stay editable
Text and shapes — layers that are not made of pixels