PDF Stamper

PdfStamper overlays text on existing PDF pages using incremental updates. Supports positioned text stamps, diagonal watermarks, page numbers, headers, and footers.

Opening a PDF

use Phpdftk\Pdf\Toolkit\PdfStamper;

// From file
$stamper = PdfStamper::open('report.pdf');

// From string
$stamper = PdfStamper::openString($pdfBytes);

// Encrypted PDF
$stamper = PdfStamper::open('secured.pdf', password: 'secret');

Watermarks

Add a diagonal watermark across all pages:

$stamper->watermark('DRAFT');

Customize the watermark appearance:

use Phpdftk\Pdf\Toolkit\Stamper\WatermarkStyle;

$stamper->watermark('CONFIDENTIAL', style: new WatermarkStyle(
    fontSize: 72.0,
    r: 1.0, g: 0.0, b: 0.0,  // red
    opacity: 0.2,
    rotation: 55.0,
));

Apply to specific pages only:

use Phpdftk\Pdf\Toolkit\PageSelector;

$stamper->watermark('DRAFT', pages: PageSelector::range(1, 3));

WatermarkStyle defaults

Property	Default	Description
fontSize	60.0	Font size in points
r, g, b	0.8, 0.8, 0.8	Light gray color
opacity	0.3	Semi-transparent
rotation	45.0	Degrees counter-clockwise

Text stamps

Place text at a predefined position on the page:

use Phpdftk\Pdf\Toolkit\Stamper\StampPosition;

$stamper->stampText('APPROVED', StampPosition::TopRight);

Available positions

Position	Location
StampPosition::TopLeft	Top-left corner
StampPosition::TopCenter	Top center
StampPosition::TopRight	Top-right corner
StampPosition::Center	Page center
StampPosition::BottomLeft	Bottom-left corner
StampPosition::BottomCenter	Bottom center
StampPosition::BottomRight	Bottom-right corner

Stamp style

use Phpdftk\Pdf\Toolkit\Stamper\StampStyle;

$stamper->stampText('APPROVED', StampPosition::TopRight, style: new StampStyle(
    fontSize: 14.0,
    r: 0.0, g: 0.5, b: 0.0,  // green
    opacity: 0.8,
));

StampStyle defaults

Property	Default	Description
fontSize	12.0	Font size in points
r, g, b	0.0, 0.0, 0.0	Black
opacity	1.0	Fully opaque

Page numbers

$stamper->addPageNumbers();
// Default: "Page 1 of 10" at bottom center

Customize format and position:

$stamper->addPageNumbers(
    position: StampPosition::BottomRight,
    format: '{n} / {total}',
);

The {n} and {total} placeholders are replaced with the current page number and total page count.

Headers and footers

Convenience methods that stamp text at TopCenter or BottomCenter:

$stamper->header('Acme Corp - Quarterly Report');
$stamper->footer('Confidential - Do Not Distribute');

Both accept optional style and pages parameters:

$stamper->header(
    'Internal Only',
    style: new StampStyle(fontSize: 8.0, r: 0.5, g: 0.5, b: 0.5),
    pages: PageSelector::odd(),
);

Chaining and saving

All operations are fluent and can be chained:

PdfStamper::open('report.pdf')
    ->watermark('DRAFT')
    ->addPageNumbers(StampPosition::BottomCenter)
    ->header('Acme Corp')
    ->save('stamped.pdf');

$bytes = $stamper->toBytes();

Document info

$stamper->getPageCount(); // int

Escape hatch

$reader = $stamper->getReader(); // PdfReader