How to use layers in a mind map

Decide what each layer holds

A layer in Canvasola is a scope for the same map. The nodes, the tree and the links all stay in one document, but the layer tabs let you look at one part of it at a time. That is the difference between a layer and a separate file: you do not lose the connection between the parts, you simply stop seeing them all at once.

Give each layer one job before you start building it. Common splits are depth planes such as context, current state and future state, or kinds of content such as claims, evidence and open questions. A layer with two jobs is one you will keep scrolling through, and the branching rules guide covers keeping each branch to one idea.

The number of layers is capped at eight, and that cap is a useful constraint. It stops you making a layer for every idea. If you are heading for a ninth, the split is probably an outline problem rather than a layer problem, and a shallower map with better labels will serve you better.

• Layers are scopes on one map, not separate maps
• Give each layer one job you can name in a few words
• Eight layers maximum
• If you need a ninth, the split is wrong

Switch the map to a single layer

Each layer tab narrows the map to the scope you are working on, so branches from other layers stay out of the way while you edit. Press 2 to edit the current layer in 2D, and use the tabs to move between them. The map itself does not change when you switch; only what is drawn does.

Scoping is what makes a layered map practical. Without it, a five-layer map is one huge drawing that you zoom around and lose your place in. With it, each layer is a small map you can hold in your head, and the whole is still a single document you can search, export and print.

Switching layers is cheap, so use the tabs as a working habit. Build on one layer, tab across to check the others still make sense, and tab back. The shortcut cheat sheet lists the layer and 3D keys, including 2 and 3.

• The layer tabs scope what is shown in the editor
• 2 edits the current layer in 2D
• Switching layers does not change the data
• Tab across layers to check consistency as you build

Note: Search runs on the active map. Before you commit to a layered structure, search for a word you know sits on a different layer and see whether it comes back, so you know how you will find things later.

Add content layer by layer

Build one layer at a time, and finish it before starting the next. A half-built layer and a layer that does not exist cause the same problem, but a half-built layer still shows up when you switch tabs, which reminds you it is unfinished.

Deleting a layer keeps its nodes, so removing a layer is not a way to throw work away. If a layer turns out to be the wrong split, delete it, and the nodes move back into the map rather than disappearing. That makes the layer structure cheap to change while you are still working out the split.

Every node carries a layer of its own, so content can be reassigned as the structure settles. When you are unsure where something belongs, leave it on the layer you are working on and move it later. A map one layer deep and correct beats a map four layers deep and speculative.

• Finish one layer before starting the next
• Deleting a layer keeps its nodes
• Reassign a node's layer as the structure settles
• A half-built layer stays visible, and that is a feature

Read the stack in 3D

Press 3 and the map moves into the 3D layer stack, where each layer sits on its own depth plane instead of flat on the screen. The camera has presets for stack, front, side and free, so you can look at the layers as a pile, as a face-on set of planes, or from the side, where the separation between them is obvious.

The explode slider pushes the planes apart along the depth axis. It is the fastest way to see how much distance sits between two layers and whether a relationship crosses a wide gap. Pair it with the side camera and your map becomes a diagram of its own layers, which the 3D layer stack guide shows in more detail.

You can also export a PNG of the 3D view, which is useful when the layered structure is the thing to show rather than the content. The stack needs WebGL, so on a machine without hardware acceleration the 3D view will not open and you stay in the flat 2D view.

• 3 opens the 3D stack and 2 returns to 2D editing
• Camera presets: stack, front, side and free
• The explode slider separates the planes along the depth axis
• The 3D view needs WebGL to run

Trace a link between two layers

In the 3D stack, press T to turn on trace mode. Trace mode highlights the links that cross between layers, which is the one thing a flat view cannot show you. A link running from a decision on one layer to a consequence on another is easy to miss in 2D and obvious in the stack.

Trace mode is also the way to audit a layered map. Turn it on, look for links that jump several layers at once, and ask whether those jumps are the ones you meant. A link that skips two layers usually means the middle layer was missing a node.

If a lot of links need to cross planes, the link count is worth checking as well. Canvasola allows up to 4,000 cross links in one map, but a small number of cross-layer links is far easier to read than a web of them. The cross links guide covers how to keep link use readable.

• T toggles trace mode in the 3D stack
• Trace highlights the links that cross between layers
• A link that skips two layers usually means a missing node
• A handful of cross-layer links reads better than a web

Export a multi-layer map

A multi-layer map round-trips through Markdown and OPML with a [layer:N] tag on each item, so a map you split into layers comes back with its layers intact when you re-import it. That is the reason to use layers rather than separate maps: the structure survives a trip through a format other tools can read.

Picture exports are per view. SVG and PNG capture what is on screen, so export the layer you want to show. If you need the whole layered structure in one image, export a PNG of the 3D view instead, since that is the only view where the layers are visible together.

Before you export at all, check that each layer still has a clear name, because the layer name is what a reader sees in the exported outline. A layer called "Layer 2" tells a reader nothing, and the export is where that shows up most clearly.

• Markdown and OPML round-trip layers with a [layer:N] tag
• SVG and PNG capture the layer you are looking at
• Export a PNG of the 3D view for the whole structure
• Name each layer clearly before exporting

A checklist you can reuse

• Every layer has one job that you can name in a few words
• The map uses eight layers or fewer
• Content was built one layer at a time, finishing each before the next
• The 3D stack was used to check the separation between layers
• Trace mode was used to review the links that cross between layers
• Each layer was named clearly before the map was exported

Common mistakes to avoid

• One layer per idea. Layers are for a handful of scopes, not for every subject. Eight is the maximum, and reaching for the ninth usually means the branches need better labels instead of a new plane.
• Deleting a layer expecting the nodes to go. Deleting a layer keeps its nodes, so the content returns to the map rather than disappearing. That is a safety net when the split is wrong, not a delete button.
• Skipping trace mode. Links that cross between layers are invisible in the flat view. Turn on trace mode in the 3D stack and check them before you believe the map is finished.
• Exporting a whole map that only shows one layer. SVG and PNG capture the current view, so a one-layer export can misrepresent a map you described as layered. Export each layer, or export a PNG of the 3D stack.

Frequently asked questions

How many layers can a mind map have?

Eight layers maximum. Each layer holds its own nodes, and the layer tabs narrow the map to the one you are working on. If you need more than eight scopes, the structure is better handled by branching or by splitting the subject into a second map, not by adding planes.

Do layers survive export and import?

Multi-layer maps round-trip through Markdown and OPML, where each item carries a layer tag so the layers come back with the structure. Picture exports such as SVG and PNG capture the current view instead, so export a layer at a time or export the 3D view.

Do I need WebGL to use layers?

Only for the 3D stack. The 2D layer tabs, the layer contents and the export behavior work without it. The 3D view, with its camera presets, explode slider and trace mode, needs WebGL and will not open on a machine without hardware acceleration.

This guide is part of the mind mapping guides collection. For the wider product tour, read the complete Canvasola guide, and keep the keyboard shortcut cheat sheet open while you work.