Using text boxes and callouts on a PDF

Sometimes a note needs to be seen without anyone opening it. A label on a drawing, an instruction on a form, an explanation beside a chart. A sticky note hides its words behind an icon, which is not what you want there. A text box puts the words on the page in plain view, and a callout adds a line and arrow so there is no doubt what they refer to.

In PDF by Zaweba, Text box places text on the page. Callout adds a text box with a leader line and arrow to the point it is about.

When a text box is right

Use a text box when the words need to be read at a glance. Labels on a plan, a "Please sign both copies" instruction at the top of a letter, a short explanation on a slide or a correction written beside a paragraph all suit it.

A text box is a comment, so it can be moved, resized, listed in the Comments panel and exported with other comments. Comment properties change its colour, fill, border width and opacity, which helps it stand out against a busy page or blend into a quiet one.

When a callout is better

A callout earns its place when the thing you are talking about is small or crowded. On a technical drawing with dozens of parts, a text box near the right part may still be ambiguous. A callout's leader line and arrow end exactly on the point it describes, so there is no doubt.

Callouts are the classic tool for annotated screenshots and diagrams: "Click here", "This value is wrong", "Join these two pieces". The box sits in clear space, and the arrow reaches into the busy part of the picture.

Making them read well

Keep the words short. A text box on a page is read in passing; three lines is plenty. If you need more, a sticky note or a pop-up note may suit better.

Put the box in clear space. Covering important parts of the page with a text box makes the page harder to read. For a callout, park the box in the margin or an empty area and let the arrow do the reaching.

Use colour with purpose. A pale fill behind dark text is readable on most pages. Matching the colour to the reviewer or to the kind of comment helps a crowded page stay clear.

How they fit with other tools

Text boxes and callouts sit between sticky notes and shapes. Sticky notes are for longer remarks hidden behind an icon. Shapes, lines and arrows draw attention without words. Text boxes and callouts combine words and position.

For a fully annotated diagram, a common mix is a few callouts for the main points, a cloud round a problem area and highlights on the relevant text. In the Comments panel, all of them appear in one list, ready to sort by page or reply to.

When a document is finished and you want the labels to become part of the page for good, flattening comments fixes them into the page.

Tangles and private remarks

Overlapping boxes are the commonest. When callouts cross each other, the page becomes a tangle. Spread them round the edge and keep leader lines from crossing.

Another is using a text box for a private remark. Text boxes are visible to everyone, including on paper. Use a sticky note for comments meant for the reviewer, not the final reader.

Used clearly, text boxes and callouts in PDF by Zaweba turn a page into something that explains itself.