watermark type
Transparent watermark for a PDF
A transparent watermark is drawn with partial opacity, so the document shows through it. Transparency is not a separate style so much as a setting that applies to every style we offer, and it is the single control that decides whether a watermark helps or hurts readability.
The same watermark at 20% opacity
Choosing an opacity
Opacity is the balance between being seen and being read through. There is no single correct value, but there are useful bands, and picking the right one is most of the work.
| Opacity | Effect | Best for |
|---|---|---|
| 8-12% | Barely there, visible on close inspection | Letterheads, subtle branding |
| 15-25% | Clearly visible, text comfortably readable | DRAFT, COPY, SAMPLE marks |
| 30-45% | Prominent, still readable on light pages | CONFIDENTIAL on business documents |
| 60-100% | Dominant, content behind it is obscured | Specimen documents, proofs |
Guidance based on our own rendering tests across A4, Letter and A3 pages.
Why darker is not safer
It is tempting to assume a heavier watermark protects a document better. In practice it usually backfires: a mark that obscures the text gets the document printed twice or abandoned, and the reader learns to treat your watermarks as a nuisance rather than a signal. A tint at 20-25% is still impossible to miss on a printed page while leaving the content fully usable.
Opacity also interacts with colour. Dark ink at low opacity reads far more strongly than a light grey at the same setting, so a deep red at 20% looks heavier than pale grey at 40%.
Transparency behind the content
Opacity and layering are separate decisions. A mark can be transparent and still sit on top of the text, or be drawn behind it entirely. Behind-the-text plus low opacity is the combination for branding that never interferes; on-top plus moderate opacity is the combination for status stamps that must be seen.
Frequently asked questions
What is the right opacity for a CONFIDENTIAL watermark?
Around 25-35% works for most business documents: unmistakable at a glance, while body text underneath stays readable. On pages with a lot of small text, drop to about 20% and consider the Behind the text style instead.
Does lowering opacity make the watermark easier to remove?
No. Opacity and removability are unrelated. A faint watermark is embedded in the page content exactly like a dark one, so removing it takes the same effort. What changes removal difficulty is the style: a tiled pattern is much harder to erase than a single mark, regardless of opacity.
Will a transparent watermark show up when printed?
Yes. Transparency in a PDF is a real colour value rather than a screen effect, so it prints. Printed tints often appear slightly stronger than on screen because of dot gain, so a 25% watermark may look like 30% on paper.