Document watermarks

Open the Watermark demo to change the text, layout, opacity, rotation, and output targets while using the same Continuous PDF workspace as the other demos.

A watermark is a Viewer policy, not an annotation. Configure it once and choose independently whether it appears while viewing, printing, and exporting.

Configure before loading

Set the policy before load() so the first rendered Continuous pages already contain the watermark:

core.viewer.setWatermark({
  text: `${currentUser.name} · ${documentId}`,
  layout: 'repeated',
  opacity: 0.12,
  rotation: -28,
  targets: {
    viewer: true,
    print: true,
    export: true,
    thumbnails: false
  }
})

await core.load({ url: '/documents/review.pdf' })

Use layout: 'center' for one centered mark. Repeated layout is usually more effective for review copies because cropping one area does not remove every occurrence.

Update or remove the policy

setWatermark() replaces the complete policy. After changing it, rerender or reload pages already visible in your application:

core.viewer.setWatermark({
  text: 'INTERNAL REVIEW',
  layout: 'center',
  opacity: 0.18,
  rotation: -20,
  targets: { viewer: true, print: true, export: false }
})

core.viewer.setWatermark(null) // remove it

getWatermark() returns a detached snapshot that can be passed to PDF output builders.

Carry it into export

Viewer Canvas and generated PDF files are separate output paths. Pass the current policy when building an exported PDF:

import { buildAnnotatedPdf } from '@inklayer-dev/core/export/pdf'

const watermark = core.viewer.getWatermark()
const output = await buildAnnotatedPdf(sourceBytes, annotations, {
  annotationTypes: core.annotationTypes,
  ...(watermark === null ? {} : { watermark })
})

The demo's Print action uses the print target. Its Export action uses the export target and downloads inklayer-watermarked.pdf.

For text outside WinAnsi, pass watermarkFontBytes. Core subsets custom fonts by default. If the supplied font cannot be subset reliably, set watermarkFontSubset: false; the complete font is then embedded and the PDF can become substantially larger.

Security boundary

Watermarks discourage casual redistribution and can identify a user or review copy. They do not encrypt the PDF, prevent editing, prove authenticity, or replace access control and certificate-backed digital signatures.

For font embedding, password-protected documents, raster printing, and secure redaction, continue with Print, export, and watermarks.