How to Use PaperThePDF

⚡ Quick Start (Under 60 Seconds)

If you just want a quick result, here is the fastest path:

1. Drop your PDF onto the upload zone.
2. Select the Classic profile for a standard black-and-white office scan.
3. Click ⬇ Download Scanned PDF.

For more control — watermarks, signatures, aging effects, per-page settings — read the full guide below.

1. Uploading Your File

Supported File Types

How to Upload

You can upload a file in two ways:

• Drag and drop — drag your file from your file manager and drop it anywhere on the dashed upload zone.
• Click to browse — click the upload zone to open your device's file picker.

Once uploaded, the file name, page count, and a live preview of the first page appear immediately. A blue "Change" button lets you swap the file at any time without losing your current settings.

File Size Limit

The maximum file size is 50 MB. For PDFs larger than this, split the document first (your PDF viewer's Print-to-PDF feature can export a page range) and convert each part separately.

2. Style Profiles

Style profiles are one-click presets that apply a curated combination of settings. They are the fastest way to get a great result.

Selecting a profile instantly applies all its values to the settings sliders. You can then continue to fine-tune individual controls — the profile label changes to "Custom" to show you've deviated from the preset.

3. Scan Settings

Every setting is reflected in the live preview as soon as you move the slider, so you can dial in exactly the right look.

Grayscale

Toggle this on to convert the document to black and white, replicating a monochrome flatbed scanner. When enabled, a slight contrast reduction is applied to flatten tonal range, mimicking how real scanners compress highlights and shadows.

Intensity

Controls the overall strength of all scan artefacts (blur, noise, JPEG compression). Scale:

• 0.5 — very subtle, barely visible artefacts. Good for "almost clean" documents.
• 1.0 — realistic everyday office scanner. This is the default.
• 1.5 — noticeable scanner noise and softness. Older flatbed or a worn document.
• 2.0 — heavy artefacts. Very old or low-quality scanner.

Paper Tilt

Applies a random rotation of ±(value)° per page. Real scanners rarely feed paper perfectly straight. A value of 0.8° is realistic for hand-fed documents; 0.3° is more precise (auto-feeder); 2–3° is noticeably crooked.

Output DPI

Sets the render resolution for the output PDF:

• 72–100 DPI — screen-only quality. Very fast conversion, small file.
• 150 DPI — fast, suitable for email or web sharing.
• 200 DPI — balanced default. Matches most office scanners on "Normal" setting.
• 300 DPI — high quality for printing or archiving. Conversion takes longer and produces larger files.

Paper Tone

Per-Page Settings

Each page can have its own settings. Navigate to the page in the preview panel, adjust the sliders, then navigate to another page — the settings are remembered per-page. Pages without overrides use the global settings. This allows, for example, a colour cover page and grayscale interior pages.

4. Paper Aging Effects

Paper aging effects add physical wear marks that make a document look genuinely old and handled. They are applied after paper tone and grayscale — so they match the chosen paper colour — but before rotation, blur, and noise — so the marks look physically scanned, not digitally overlaid.

All four effects can be combined. Each is deterministic per page (uses the page number as a seed) so the same page always produces the same aging positions, ensuring consistent output on repeated conversions.

☕ Coffee Stain

Overlays a semi-transparent coffee-ring stain. The ring uses a warm brown colour with a slight ellipse shape and a faint brownish wash inside. Position and radius vary subtly between pages.

📄 Fold Crease

Simulates a horizontal fold crease running across the middle of the page at a slight angle (±1.5°). A thin bright highlight marks the fold ridge; a soft shadow falls below it, replicating the way paper reflects light differently at a fold.

📐 Dog-Ear

Folds the top-right corner of the page. The folded triangle shows the "back" of the paper in an off-white cream colour with a darker crease line, and a subtle shadow where the fold begins.

🔘 Hole Punch

Adds three standard three-ring binder punch holes on the left margin. Each hole has a pressed-fibre shadow ring around it, matching how a physical hole punch compresses the paper edge.

5. Watermarks

The watermark feature lets you overlay any text across all pages of the document. The watermark is composited before scan effects are applied, so it appears physically printed or stamped on the paper — not digitally overlaid after scanning.

Adding a Watermark

1. Scroll to the Watermark section in the settings panel.
2. Type your watermark text (e.g. CONFIDENTIAL, DRAFT, COPY).
3. The preview updates immediately.

Watermark Modes

Tiled Mode — the watermark text is repeated in a staggered grid across the entire page. This is the standard approach for confidentiality watermarks.

Custom Position Mode — a single watermark is placed at a specific point on the page. In the preview panel, a draggable marker appears; drag it to position the watermark exactly where you want it.

Watermark Settings

6. Annotations — Signatures & Stamps

Annotations let you place signatures, rubber stamps, or custom text stamps on any page. Like watermarks, annotations are composited before scan effects — so they appear physically signed and then scanned.

Adding a Signature

Click ✒️ Signature in the Annotations section to open the Signature modal.

1. Upload your signature image — a photo on white paper, or a PNG scan of your handwritten signature.
2. Crop — drag the crop handles to isolate just the signature and exclude blank margins.
3. Adjust threshold — the slider controls background removal sensitivity. Move it until only the ink is visible (the background becomes transparent).
4. Click Use This Signature — the signature appears as an overlay in the preview.

Once placed, you can:

• Drag it to reposition
• Resize using the corner handles
• Rotate using the circular handle above it
• Adjust opacity using the slider in the annotation toolbar
• Delete it using the × button

Stock Stamps

Click 🔖 Stamp → Stock Stamps tab to browse the built-in stamp library. Clicking a stamp image processes it (removes the white background) and places it on the current page. Resize and reposition as needed.

Text Stamps

Click 🔖 Stamp → Text Stamp tab to generate a custom rubber-stamp annotation:

1. Enter your stamp text (e.g. APPROVED, RECEIVED, PAID).
2. Choose a colour and font size.
3. Select a style: Box (text in a rounded rectangle border), Circle (text in an ellipse), or Plain (text only, no border).
4. Click Add Stamp.

Annotation Scope

By default, annotations are placed on the current page only. You can change the scope to All Pages to apply the annotation to every page simultaneously — useful for "CONFIDENTIAL" or "COPY" stamps that should appear throughout the document.

7. Live Preview & Compare

Live Preview Panel

The right panel shows a real-time preview of the current page with all scan effects applied. Any change to the settings re-renders the preview automatically (with a short debounce to avoid re-rendering on every slider tick). The preview renders at 150 DPI for speed.

Page Navigation

For multi-page PDFs, a thumbnail strip appears on the right side of the preview panel. Click any thumbnail to jump to that page. Prev / Next arrows appear at the bottom of the main preview image for sequential navigation.

Compare Slider

Click the ⊞ Compare button at the top-left of the preview panel to activate split-view mode. A vertical slider appears that you can drag left and right to reveal the original page on the left and the scanned version on the right. Click Compare again to exit split-view mode.

8. Page Range Selection

For multi-page PDFs, you can choose to convert only a subset of pages. The 📑 Pages input appears at the bottom of the settings panel once a multi-page PDF is loaded.

Syntax

Page numbers are 1-indexed (the first page is "1"). Pages are processed in the order specified. The output PDF and ZIP filenames use the original page numbers so they remain meaningful.

9. Exporting Your Document

Download Scanned PDF

Click ⬇ Download Scanned PDF to begin a full-resolution conversion. A progress bar appears showing real-time page-by-page progress (e.g. "Page 3 / 12"). When conversion completes, a green ⬇ Save Scanned PDF link appears — click it to download the file.

The output filename is [original-filename]_scanned.pdf.

Export as Images (ZIP)

Click 🗜️ Export as Images (ZIP) to convert each page to a high-resolution JPEG and pack them into a ZIP archive. This is useful when you need individual page images rather than a single PDF.

Each image is named page_NNN.jpg (e.g. page_001.jpg) using the original page number, so filenames are meaningful even when converting a page range.

The ZIP uses STORE compression (no re-compression) since JPEG images are already compressed — this keeps the ZIP creation fast.

Progress Tracking

Both exports display real-time per-page progress via a Server-Sent Events stream. You can watch exactly which page is being processed. The progress bar stays visible until the download link appears, so you always know the status of a long conversion.

10. Saving & Loading Custom Profiles

Once you have configured a combination of settings you like, you can save it as a named profile for future use.

1. Adjust all settings to the desired state.
2. Click 💾 Save as profile… below the preset cards.
3. Enter a name for your profile (e.g. "My Signature Style").
4. Click Save. Your profile appears in the profile picker as a Custom card.

Profiles are stored in your browser's localStorage — they persist across sessions on the same browser and device. They are never sent to our server. You can save up to several profiles and switch between them instantly.

⭐ Pro Tips

Achieve the Most Realistic Results

• Use Intensity 1.0–1.2 with Warm paper tone and Tilt 0.5–1.0° for a convincing office scanner look.
• Enable Coffee Stain + Fold Crease for documents meant to look filed and retrieved.
• Set the watermark opacity to 12–18% for a subtle but readable confidentiality stamp.
• For signatures, photograph your handwritten signature against clean white paper in good lighting for the best background-removal result.

Speed Up Large Conversions

• Use 200 DPI instead of 300 DPI — you get 75% of the quality at roughly half the conversion time.
• Disable aging effects (especially Coffee Stain) if not needed — they involve NumPy array operations that add time per page.
• Use the Page Range field to convert only the pages you need for a first check, then convert all pages for the final export.

Keyboard & Workflow Tips

• The Change button swaps the file without resetting your settings — useful for applying the same style to multiple documents.
• Saving a profile before starting a multi-document job ensures you apply identical settings every time.
• The Compare slider works best when you start from the centre and drag slowly — the reveal is smooth and precise.