You want to comment on a chart's misleading axis. Highlighting the axis is hard (it's a thin line). A rectangle around the whole chart says 'this thing'. A circle around the suspicious data point says 'that thing'.
Shapes communicate region-level concerns. Flint has them.
Available shapes
Open annotate PDF: rectangle, ellipse, line, polygon. Each is drag-to-draw. Rectangles for paragraphs, sections, charts. Ellipses for individual elements, data points, icons. Lines for connecting two points or marking alignment. Polygons for irregular regions.
Style: outlined or filled
Outlined shapes preserve underlying content visibility — you can still read what's inside the rectangle. Filled shapes obscure (unless you use semi-transparent fill). Most review annotations use outlined; emphasis annotations sometimes use semi-transparent fill.
Group shape with comment
Like arrows, shapes are stronger with attached commentary. Right-click a shape, add a sticky note. Or place a text annotation nearby. The shape tells the reader where to look; the comment tells them what to think about.
Editing after placement
Click any shape to select. Drag corners to resize. Drag the body to move. Adjust colour and thickness via the properties panel. Delete with the delete key. Shapes are fully editable until you save and close the document.
FAQ
Can shapes be transparent?
Yes — set fill opacity. Outlined-only shapes have no fill at all (most see-through).
Do shapes affect text selection?
No. They sit on top but don't block selection of underlying text.
Can I copy a shape?
Yes, in most readers. Cmd/Ctrl+C to copy, Cmd/Ctrl+V to paste. Useful for repeating consistent markup.
Will shapes print?
Yes by default. Toggle 'don't print annotations' to print without them.
Box it, circle it, line it up. Annotate with shapes.