Clear formatting + Paint format

What it does

Clear formatting — select a range and press Ctrl+\ (or click the Tx button in the toolbar) to reset every presentation attribute back to default: no bold/italic/strike, no font/color/fill overrides, no borders, no explicit number format, no alignment/wrap override. The cell's value or formula is never touched — clearing the format on =A1+B1 resets its styling without changing what it computes to. It undoes and redoes like any other edit, and applying it to a range is one undoable command.

Paint format — the roller icon in the toolbar copies a range's full format onto another range, exactly like Google Sheets' format painter:

• Single click arms a one-shot paint: your very next click (or shift-click to extend to a range) applies the copied format and the tool immediately disarms.
• Double click arms a sticky paint: it stays armed across repeated applies — keep clicking new targets — until you press Escape or click the roller again.

Applying replaces the target's format wholesale, the same way Sheets does: if the target had its own border or fill that the source didn't carry, painting removes it too — this isn't a merge of the two formats. Painting onto a range bigger than the captured source tiles the source pattern across it (Sheets' own repeat-the-pattern behavior). A multi-cell apply is one undoable command regardless of size.

Verification

The scenario runner can drive Ctrl+\ end-to-end (a real keyboard chord), so clear-formatting's scenarios above are fully automated. Paint format's arm/apply gesture is a toolbar click followed by a click on a DIFFERENT target cell — the runner has no verb for driving a toolbar action button yet (the same gap format-fill-color.mdx documents for its color swatch), so it's browser-verified instead: arming via a single click on the roller shows the pressed toolbar state and the source range gets a dashed "copying" outline; clicking a target cell applies the source's format, replaces the target's own prior formatting, and the roller un-presses itself (one-shot); double-clicking the roller instead keeps it pressed across repeated target clicks until Escape.

Verified behavior

Matches Google Sheets: In Google Sheets, Format → Clear formatting (Ctrl+\ / Cmd+\ on Mac) resets every presentation attribute on the selection — bold/italic/strikethrough, fonts, colors, borders, number format, alignment, wrap — back to the default, without touching the cell's value or formula. It undoes/redoes like any edit. The Paint format toolbar button (the roller icon) captures the CURRENT selection's format pattern: a single click arms a ONE-SHOT paint that applies to the next click/drag target and immediately disarms; a double click arms a STICKY paint that stays armed — repeatedly applying to each subsequent click/drag target — until Escape is pressed or the roller is clicked again. Applying replaces the target's format wholesale (not a merge): a target's own fill/border/etc. that the source didn't carry is cleared too. A multi-cell target range is one undoable command regardless of size.

Ctrl+\ resets a bold+bordered cell's format, value unchanged

Given

• A1 = hello

When I click A1, then press Control+b, then press Control+Shift+7, then press Control+Backslash

Then

• A1 shows hello
• A1 is bold=false, borders=false

Ctrl+\ on a formula cell clears format only — value and formula survive

Given

• A1 = 5
• A2 = =A1*2

When I click A2, then press Control+b, then press Control+Backslash

Then

• A2 shows 10
• A2 has formula =A1*2
• A2 is bold=false

Ctrl+\ a second time is a no-op (already-default format stays default)

Given

• A1 = hello

When I click A1, then press Control+Backslash, then press Control+Backslash

Then

• A1 shows hello
• A1 is bold=false

Selecting a formula cell leaves its value and formula unchanged (presentation-independence)

Given

• A1 = 5
• A2 = =A1*2

When I click A2

Then

• A2 shows 10
• A2 has formula =A1*2