Signature module

The Sign module lets you apply a visual signature to a PDF — either by typing a name in a typeface of your choice, or by importing an image (a handwritten signature that has been scanned or photographed). The module is available from the Security category of the Dashboard.

Nature of the signature

⚠️ Important: the Sign module adds a visual signature to the document. It is not a cryptographic digital signature in the strict legal sense (eIDAS, PAdES). For uses where non-repudiable proof of authenticity is required (high-stakes commercial contracts, official deeds), turn to qualified electronic signature solutions such as DocuSign, Yousign, or the macOS Markup & Preview signature feature directly.

A visual signature nevertheless remains perfectly suited to:

• signing quotes, purchase orders or statutory declarations;
• internal signing of collaborative documents;
• applying initials or a company seal.

Adding a text signature

The New Signature section offers two complementary modes.

Text signature

1. Type your name (or another wording) in the Text field;
2. Choose whether you want a Handwritten Style (the Snell Roundhand font, which mimics cursive writing) or a standard typeface (Helvetica);
3. Click Add Text.

The signature appears in the center of the page currently displayed. You can then move and resize it directly in the PDF view, like any annotation.

Editing an existing signature

Click a signature in the Added Elements list (which appears as soon as at least one signature has been placed) to select it. An Edit Signature section is then shown, offering:

• Font: a drop-down menu listing every font installed on your Mac. You are therefore not limited to Snell Roundhand — any font on your system can be used;
• Size: a slider from 8 to 72 points;
• Color: a standard macOS color picker;
• Bold / Italic: switches for the style variants;
• Delete: removes the signature from the document.

Changes are applied in real time to the selected signature. To change the text itself of a placed signature, delete it and create a new one.

Importing a signature image

To use a real handwritten signature:

1. Scan or photograph your signature on a light background, then save it in PNG format (preferably with a transparent background) or JPEG;
2. In the Sign module, click Import Image…;
3. Select the image file in the open panel (accepted formats: PNG, JPEG, TIFF);
4. The signature is added in the center of the current page.

As with text signatures, you can then move and resize the image directly in the PDF view. An image signature, however, cannot be edited from the sidebar (font, color, and so on): to adjust those aspects, retouch the source image file before importing it again.

Tip: for a signature that fits cleanly into any document, create a transparent PNG image of your signature with an image editor (Preview, Pixelmator, and so on). Transparent areas will not mask the surrounding text, unlike a JPEG with a white background.

List of added elements

The Added Elements section lists every signature (text and image) present in the document, giving for each one:

• the type icon (text or image);
• the content (or "Image" for imported signatures);
• the page it is placed on.

Clicking an entry:

• selects the signature in the PDF view;
• automatically scrolls the document to the page concerned;
• opens the Edit Signature section (for text signatures only).

Confirming and history

Signatures are ordinary PDF annotations. Like the others:

• they can be undone through the Undo button at the top of the sidebar;
• each addition or change creates a checkpoint in the History;
• they stay in pending changes until they are explicitly saved from the Dashboard (⌘S).

Making the signature tamper-proof

A placed signature remains an editable annotation: it can be moved, deleted or covered by any third-party PDF reader. For a final signature intended for distribution:

1. Check the positioning and size of your signature;
2. Open the Flatten module from the Editing category;
3. Click Flatten document.

Flattening freezes the signature into the page content: it can no longer be modified, moved or deleted by a third-party PDF editor. Combine this with password protection (Protect module) to also prevent the document being modified by adding other annotations.

Screenshots

1 screenshot — click to enlarge

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