How to annotate a document

Decide what kind of mark you need

Annotation is a small vocabulary: a circle around something, an arrow pointing at it, an underline beneath it, a line through it, and a block of color behind it. Work out which of those five the reader needs before you draw, because each one means something different and mixing them weakens the message.

A circle says look here. An arrow says look here and this is the direction of attention. An underline says this sentence matters. A strike-through says this is wrong. A block of color says this region belongs together, and it is the only one of the five that needs a filled shape.

Knowing which mark you need saves most of the work, because a mark that is too heavy for its message turns a document into a mess of noise. One arrow per point is plenty on a page of reading.

• Circle: look at this
• Arrow: look here, and follow this direction
• Underline: this sentence matters
• Block of color: these lines belong together

Drawing arrows and underlines in ink

There are two ways to make a mark: the tools that give you exact geometry, and the brushes that give you a hand. Press U for the Shape tool and choose the Arrow for a pointer, or the Line for an underline. Drag from one point to another and the mark lands where you dragged it.

The brushes are the other half. The Smooth Pen draws a clean underline under a sentence, and the Crayon/Chalk brush gives a softer, rougher line that reads as a pencil mark rather than a printed rule. Both are freehand, so they follow the shape of the line under them.

A hand underline follows the text and an arrow shape cuts across it, so decide which one the reader will understand. The shape guide covers stroke width and color, and the drawing guide covers the brushes.

• U, then Arrow or Line, then drag
• Smooth Pen for a clean underline
• Crayon/Chalk for a soft pencil-like mark
• Match the mark to the message

Highlighting a phrase with a translucent fill

A highlight is a rectangle with a fill and no stroke, and the trick is the opacity. Draw a rectangle over the phrase, set the fill to the highlighter color you want, and lower the opacity in the Appearance flyout to around 30 percent so the text below stays readable.

Switch the stroke off as well, because a visible border turns a highlighter into a box and makes the reader look at the shape rather than the words. The Fill Options flyout switches the fill on, the Stroke Options flyout switches the outline off, and the two are independent.

One rectangle per phrase, not one rectangle over the paragraph. A block of color across four lines hides the text it is meant to point at, and the opacity setting is not a substitute for a smaller shape.

• Rectangle shape, fill on, stroke off
• Opacity around 30 percent for a highlighter
• One rectangle per phrase, not per paragraph
• Blend modes are for overlaps, not for reading

Erasing a mark without losing the rest

The Eraser tool (E) removes paint along the path of the stroke. Drag it over a mark and the mark goes, which is the fastest way to clear a line drawn in the wrong place, and it works on brush strokes and shapes alike.

Be careful where you drag. The eraser clears whatever is under it, so a stroke drawn across a box outline takes the outline with it. Erase around the mark rather than through it when the rest of the page matters.

For a mark that is an element in its own right, deleting it is cleaner than erasing it. Select it with V and press Delete, and Ctrl/Cmd+Z brings it back, because the shared history keeps 20 versions of the document.

• E for the eraser, drag over the mark
• Paint under the stroke goes as well
• Delete an element instead of erasing over it
• Ctrl/Cmd+Z reverses a delete

Note: Everything here happens on the canvas and nothing happens to the file you are reading. The original document is never opened, never modified and never uploaded anywhere.

Keeping the original and the marked version apart

The workspace holds up to 100 tabs, and the titles are generated as Canvas 1, Canvas 2 and so on, so give the marked copy its own tab and leave the original where it is. Two tabs side by side in split view is the natural way to work: the original on one side, your marks on the other.

Tabs cannot be renamed, so the naming has to live in your head or in the file name you export. If you are marking several versions of one document, keep them in separate tabs in the order you made them, and export each one as you finish it.

The organizing canvases guide covers how the tab bar behaves and how to keep work recoverable, and the shortcut list has the keys for moving between modes quickly and for undoing a change you did not mean to make.

• Up to 100 workspace tabs
• Titles are generated, not typed
• Split view puts the original beside the marks
• Export each marked copy as you finish it

Exporting the marks as an overlay file

Export the marked canvas as Vector (SVG) and you get a file holding nothing but your marks on a transparent background, which is the format you want for an overlay. The marks are real vector paths, so the overlay stays sharp at any zoom and can be recolored in a vector editor afterwards.

Export as PNG gives the same overlay as a picture with a transparent background, which is easier to drop into a slide or a document editor. Export as JPG flattens the background, so it is no longer an overlay at all. Print current view opens your browser's print dialog, which is how you get a paper copy of the marked page.

Place the exported overlay over the original file in whatever you read the document in. Canvasola does not open documents and does not place images on the canvas, so the overlay is a file you import elsewhere rather than a layer inside the app, and the export guide compares the four formats in detail.

• Vector SVG for a sharp, editable overlay
• PNG for a transparent overlay picture
• JPG flattens the background and stops being an overlay
• Print current view for a paper copy

A checklist you can reuse

• Each mark was chosen for the message it carries
• The original file was left untouched in its own tab
• Highlights are translucent and one phrase at a time
• No highlight covers more than the phrase it points at
• Erasing strokes stayed clear of the content underneath
• The canvas proportions match the page being marked
• The marks were exported as an overlay in SVG or PNG

Common mistakes to avoid

• Marking the original instead of a copy. The marked page and the clean page are different documents, and you will want both. Keep the marked version in its own workspace tab and export it before you close the file.
• Highlighting with a solid rectangle. An opaque block hides the words it is meant to draw attention to. Drop the opacity to around 30 percent and switch the stroke off.
• Erasing across the page. The eraser clears everything under the stroke, including box outlines and underlines you wanted. Erase around a mark rather than through it.
• Exporting JPG as an overlay. JPG flattens the background, so the file covers the document instead of sitting on it. Use PNG or vector SVG for anything that has to sit over the original.
• Annotating at the wrong zoom. The marks are placed in canvas coordinates, not on top of the page, so a canvas at a different scale or proportion puts every mark in the wrong place. Match the proportions before you start.

Frequently asked questions

Can I open a PDF in Canvasola and mark it up?

No. There is no document viewer in the app, and no way to place an image on the canvas, so a file cannot be dropped in and marked directly. The workable route is to read the document in another window beside the canvas, draw the marks to match, and export an SVG overlay that you import over the original in your PDF reader or document editor.

How do I make the overlay line up with the original?

Match the proportions and the zoom, then place the marks by eye. The canvas has no image registration and nothing snaps to a page, so alignment is manual: draw a reference rectangle with the same proportions as the page, check the zoom percentage reads the same in both windows, and keep the marked copy in a separate tab from the original.

Can I undo an annotation that went wrong?

Yes, and in two ways. Ctrl/Cmd+Z and Ctrl/Cmd+Y move through the change history, which is shared between the canvas, the mind map and App Builder, and 20 versions of the document are kept. The Version history panel in the top bar lists those versions with timestamps, so a page that has gone wrong can be restored to an earlier state.

Is there a PDF export for the marked page?

Canvasola does not write PDF files. The Print current view action opens your browser's print dialog, and PDF is one of the destinations that dialog offers, so a marked page can reach a PDF through the browser. For a file that has to sit over an original, the vector SVG export is the better route because the background stays transparent.

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