Text Annotations

Text annotations are free-floating labels and text boxes that live on the canvas alongside your structures. You create them with the text tool, type directly into an in-place editor, and format runs of text with the formatting toolbar: bold, italic, underline, strikethrough, sub/superscript, font, size, color, highlight, alignment, and lists.

Placing text

Press T to activate the text tool.

Click an empty spot to place an auto-sizing text label and start typing. The label grows with its content and matches the current atom label font size.
Drag out a region (larger than 30 x 30 px) to create a fixed-size text box. Boxes start at font size 14 with left alignment.
Click an existing text annotation with the text tool to open its editor instead of stacking a new label on top of it.
Click an atom with the text tool to edit that atom’s label. This is a separate editor from text annotations.

The in-place editor

Typing happens directly in the rendered annotation, so what you see while editing is what renders on the canvas. The formatting toolbar appears at the top of the window while an editor is open.

Commit and cancel behavior:

Enter inserts a line break. Inside a list, Enter creates the next list item instead.
Ctrl+Enter commits the edit and closes the editor.
Clicking anywhere outside the editor also commits.
Escape closes the editor without keeping the session’s changes. If the annotation was just created and is still empty, Escape removes it.

Each edit session produces a single undo entry on the canvas. While the editor is open, Ctrl+Z and Ctrl+Y (or Ctrl+Shift+Z) step through formatting and typing changes within the session.

The toolbar applies formatting to the current selection, or sets up formatting at the cursor so the next characters you type inherit it. It offers:

Bold, italic, underline, strikethrough
Superscript and subscript, for charges and formula subscripts
Font family and font size pickers (see Fonts for adding fonts)
Text color and highlight (background color), both with live preview while you drag in the picker
Alignment: left, center, right
Bullet and numbered lists, plus a list style picker. Tab indents a list item and Shift+Tab outdents it.
Clear formatting, which strips bold/italic/underline/strikethrough and color/font styling from the selection but keeps sub/superscript and lists

Right-clicking inside the editor opens a context menu with Cut, Copy, Paste, Paste as plain text, Select all, Insert symbol, and Clear formatting.

While you type, the browser’s spellchecker underlines misspelled words. If the red underlines get in the way (chemical names trip them constantly), turn them off with Structure, then Spellcheck; the toggle applies to all text editing in the document and is on by default.

Symbol palette

The toolbar’s symbol button opens a palette with Greek letters, arrows, math and chemistry symbols, and Unicode subscript/superscript characters. Click a symbol to insert it at the cursor.

Backslash shortcuts such as \Delta and \hv expand only in arrow text zones (saved from either the inline editor or the properties panel), not in text annotations. For typeset math, use a LaTeX annotation instead.

Editor keyboard shortcuts

All verified in source.

Shortcut	Action
`Ctrl+B` / `Ctrl+I` / `Ctrl+U`	Bold / italic / underline
`Ctrl+Shift+X`	Strikethrough
`Ctrl+=`	Subscript
`Ctrl+Shift+=`	Superscript
`Ctrl+Shift+V`	Paste as plain text
`Ctrl+Enter`	Commit and close
`Escape`	Close without keeping changes
`Tab` / `Shift+Tab`	Indent / outdent in lists; outside a list, `Tab` moves focus to the toolbar

Editing, moving, and resizing

Double-click a text annotation with any tool (except pan) to reopen its editor. Double-clicking an already-selected atom edits its label (double-clicking an unselected atom selects its molecule first).
With the select tool, drag a text annotation to move it and drag the selection handles to resize it. Resizing an auto-sizing label converts it into a fixed-size box.
A text box is either auto-sizing (it hugs its content, and shows a small auto badge in its corner when selected) or fixed-size (you gave it an explicit size by dragging a resize handle, as above).
Right-click a fixed-size text box for Shrink to Text (tighten the box around its content) or Make Auto-size (drop the fixed width and height, returning the box to auto-sizing). These two options do not appear for an auto-sizing box, since it is already shrink-wrapped to its text. Ctrl+double-clicking one of a fixed-size box’s resize handles performs the same shrink-to-fit.