Your colleague sent a draft proposal as a PDF and asked for feedback by tomorrow. You'd rather not retype changes in an email — easier to mark them up in place.
Review comments in PDF are exactly this. Flint makes them easy to add.
Sticky notes for focused feedback
Open annotate PDF, drop the proposal, click anywhere to add a sticky note. Type your comment. The note appears as a small icon on the page; clicking it expands the full text. This is the standard format for review feedback — small, location-anchored, expandable.
Highlights to draw attention
For comments tied to specific text, highlight the text first, then add a comment to the highlight. Click the highlighter, drag over the relevant sentence, then click the highlight to add commentary. Now your reviewer sees exactly what you're referring to without having to guess.
Use shapes for layout comments
When you want to talk about whitespace, alignment, or page layout, draw shapes — a rectangle around an empty area to say 'add a chart here'. Annotate PDF supports rectangles, ellipses, lines, arrows. Each shape can have an attached comment.
Send the annotated file back
Save and send. Modern PDF readers (Acrobat, Preview, browser readers) show annotations naturally. The author sees your sticky notes, highlights, and shapes inline. Reply threads work in Acrobat but not all readers — for cross-tool reliability, treat each annotation as a single comment, not a conversation.
FAQ
Can the author reply to my comments?
In Acrobat yes — reply threads. In Preview and browser readers, replies are limited. For threaded review, agree on tooling upfront.
Are comments saved into the PDF or external?
Saved into the PDF as annotations. They travel with the file.
Can I export comments as a list?
Acrobat exports comments to CSV or summary PDF. Flint annotations remain in the PDF for the reviewer to see in any reader.
Do annotations affect printing?
By default yes — sticky notes show as icons when printed. Most readers have a 'don't print annotations' setting.
Mark up, send back, iterate. Add review comments.