Scan Effect Explained: What Makes a Document Look Scanned (and the Settings for 5 Looks)

A scan effect is the set of small flaws a real scanner leaves on a page: a slight tilt, sensor noise, soft focus, a warm paper tone, gray tones and JPEG compression. To make a document look scanned, reproduce those flaws in moderation, for example rotate 1°, blur 0.3, noise 0.1, Gray colorspace and 2× resolution.

A quick "add noise and tilt it" often looks like a filter, not a scan. This reference splits a real scan into its artifacts, explains each hardware cause, maps it to a control in our free scan tool, and gives five ready recipes. Hardware facts come from NARA, FADGI, BBC News and Wikipedia; slider ranges come from our own source code.

What is a scan effect?

A scan effect is a digital simulation of the visual traces an optical scanner or copier leaves on a page. The scan effect turns a clean, digitally generated file into an image-based PDF that shows tilt, noise, softness, tone shifts and compression, the same cues people use to recognize a paper scan.

The term covers several related looks. A "scanner effect" usually means the flatbed office look: gray, slightly soft, a little crooked. A photocopy look is harsher, with blown-out whites and dark text. A fax look is coarse and low-resolution. An aged-paper look adds a warm, yellowed tone. All of them are built from the same small set of artifacts, only in different amounts.

Technically, every scan effect ends the same way: each page becomes a picture. Our tool renders every PDF page to a canvas, applies the effect, and stores each page as a JPEG image inside a new PDF. That is why a scanned-look PDF, like a real scanned PDF, has no selectable text unless OCR is added later. Our guide what is a scanned PDF covers that difference in detail.

What makes a document look scanned?

A document looks scanned when several imperfections appear together: the page is slightly rotated, the whites are not pure white, fine noise sits in flat areas, edges of letters are soft, and the colors are reduced to grays. No single artifact is convincing alone; the combination is what reads as a scan.

The U.S. National Archives lists the defects its reviewers check in digitized records. According to the federal digitization rule at 36 CFR Part 1236, Subpart E, quality control looks for clipping, misregistration, quantization errors, skew and improper cropping. Those "defects" for an archivist are exactly the ingredients of the look scan artifacts create for everyone else.

Geometry

Skew and rotation, different on each page.

Texture

Sensor noise and paper grain in flat areas.

Sharpness

Optical softness from the lens and the moving scan head.

Tone

Paper color, brightness and contrast shifts.

Color depth

Grayscale or bitonal instead of full color.

Compression

JPEG 8×8 blocks and limited resolution.

Frame

Edge shadows, lid lines and page borders.

How does skew create the scanned look?

Skew is the small rotation a page gets when it is placed on the scanner glass or pulled through a document feeder slightly off-square. Skew is the most recognizable part of the scanned look, because digitally created pages are always perfectly straight, while real sheets almost never land at exactly 0°.

The cause is mechanical. FADGI, the U.S. federal digitization working group, notes in its Technical Guidelines for Digitizing Cultural Heritage Materials: "Skew behaviors in the captured image can often be traced to lack of parallelism between the focal plane of the camera and the platen." In an office, the more common cause is simpler: a hand places the sheet a degree or two off the guide.

In our tool, the Rotate slider sets the base tilt from −10° to 10° (default 1°). Negative values turn the page counterclockwise. A natural range for a flatbed scan is 0.5° to 1.5°. Values above 3° look like a careless photo, and above 5° like a deliberate effect.

Per-page variance: why each scanned page tilts differently

Rotate variance (0 to 10°, default 0.5°) adds a random extra tilt to every page. In our source code, the final angle of each page is the base rotation plus the variance multiplied by a random number between 0 and 1. With rotate 1 and variance 0.5, every page lands somewhere between 1.0° and 1.5°, never twice at exactly the same angle.

That per-page difference matters more than the angle itself. A stack of paper fed page by page never repeats the same skew, so identical tilt on 20 pages is a giveaway. Keep variance at 0.3–1° for a flatbed look and 1–2° for a hand-held phone look.

Why does a scanner effect include noise?

A scanner effect includes noise because every image sensor records small random variations that are not in the original paper. Noise shows as faint speckle in white margins and flat gray areas. Without noise, a scanned-look page is too clean, which is the most common reason a simulated scan reads as digital.

NARA defines the problem precisely in 36 CFR 1236 Subpart E: "Noise is one or more undesirable image artifact(s) in a digitized record that is not part of the source material." The same regulation sets an upper noise limit for archival scans, measured as a standard deviation of 2 or less in lightness. Real scans are therefore noisy, but only slightly.

FADGI adds the other side of the story: aggressive de-noising can erase the natural texture of paper, so its guidelines also flag noise values that are too low. A perfectly smooth page is suspicious even to an archivist.

In our tool, the Noise slider runs from 0 to 1 (default 0.1). It overlays a fine fractal texture across the whole page, including the white margins, which imitates both sensor speckle and paper grain. A natural range is 0.05–0.2. Above 0.3 the texture becomes visible at normal zoom and starts to look like an effect rather than a scan.

How much blur does a real scan have?

A real scan has a small amount of blur: letter edges are soft rather than razor sharp, and thin lines lose a little contrast. The softness comes from the scanner lens, from the scan head moving while it exposes, and from paper that does not lie perfectly flat against the glass.

Digital PDFs render text as vector outlines, sharp at any zoom. A scan has fixed resolution, and each pixel averages light from a small area of paper, which leaves a slight halo around characters.

The Blur slider in our tool runs from 0 to 1 (default 0.3). The value is a blur radius in pixels of the rendered page, so the same value looks softer at 1× resolution than at 3×. A natural range is 0.2–0.4. Above 0.6, small print becomes hard to read, and heavy blur is one of the fastest ways to make a scan effect look fake.

How does paper tone change the scan effect?

Paper tone changes the scan effect by replacing pure digital white with the slightly warm or gray white of real paper. Office paper scans a little off-white, recycled paper looks gray, and old documents turn yellow or brown. A warm tone is the main cue behind the aged-paper look.

Scanners record paper yellowing faithfully, especially in color mode, and lamps and white balance shift the tone slightly from device to device.

Our Yellowish slider (0 to 2, default 0) applies a sepia tone. In our code it is applied after the gray conversion, so it tints the page even in Gray colorspace; in Color colorspace it also warms colored elements. A natural range is 0.1–0.3 for normal paper and 0.3–0.6 for an aged or archival look.

How do brightness and contrast shape a scan?

Brightness and contrast shape a scan by setting how white the paper and how black the text appear. Office scanners and copiers often push contrast up, which darkens text and washes out light backgrounds. Brightness below 1 gives a dim, gray scan; above 1 gives a bleached, overexposed copy.

Behind both settings is bit depth, the number of tone steps a scanner stores. According to Wikipedia's image scanner article, typical scanners capture at least 24-bit color and high-quality models 36–48 bits. Grayscale scans usually store 8 bits, or 256 shades. When a scanner squeezes that range, fine gradations disappear, which NARA calls quantization.

NARA's rule puts it this way: "Quantization is a lossy compression technique that involves compressing a range of values to a single quantum value, usually to reduce file size." Raising contrast in our tool imitates the same visual result: light grays merge into white and dark grays merge into black.

Brightness

0 to 2, default 1. Natural: 0.95–1.1. Photocopy: 1.05–1.1. Aged paper: about 0.95.

Contrast

0 to 2, default 1. Natural: 1–1.2. Photocopy: 1.3–1.5. Fax: 1.5 or higher.

Grayscale or bitonal: which scanned look?

Grayscale gives the soft, even scanned look of a modern office scanner, while bitonal gives the hard black-and-white look of fax machines and court filings. Grayscale keeps up to 256 shades per pixel; bitonal keeps only two. Most people picture grayscale when they imagine a typical document scan.

FADGI defines both terms in its glossary. "Grayscale: Digital images produced using a range of grays between white and black." And: "Bitonal: Digital images produced using only two colors, black and white." Bitonal files are 1 bit per pixel, grayscale files typically 8 or 16 bits, according to the FADGI Technical Guidelines.

Our tool offers two colorspaces: Gray (the default) and Color. There is no true 1-bit bitonal mode. To approach a bitonal or photocopy look, keep Gray and raise contrast to 1.4–1.6; light grays then drop to white and text goes close to black while the file stays 8-bit. Use Color only when a logo, stamp, highlighter or aged-paper tone must show.

For plain conversion without scan artifacts, see how to convert a color PDF to black and white.

Do JPEG blocks and resolution add to the scan look?

JPEG blocks and limited resolution do add to the scan look. Most scanners save pages as JPEG images, which leaves faint 8×8-pixel blocks around text, and office scans are usually made at 150–300 dpi, so a page never has the unlimited sharpness of a vector PDF when you zoom in.

FADGI describes the compression artifact directly: "For instance, standard JPEG processing introduces 8x8 pixel blocks that are clearly not part of the original content." Those blocks are most visible around black text on white paper and in smooth gradients, as the Wikipedia article on compression artifacts also shows.

Our tool stores every processed page as a JPEG image inside the new PDF, so light JPEG blocking appears naturally, just as it does in real scanner output. The Resolution setting controls pixel density: pages render at 72 dpi multiplied by the scale.

For comparison, archival scanning goes much higher. NARA sets minimums of 300 ppi for textual records and 400 ppi for photographic prints, and FADGI star levels for unbound documents range from about 200 to 400 ppi. A scan effect does not need archival resolution; it needs to look like an everyday office scan.

What is moiré in a scanned document?

Moiré in a scanned document is a wavy interference pattern that appears when a scanner samples a printed halftone picture, such as a magazine photo or a newspaper image. The regular dot grid of the print and the regular pixel grid of the sensor clash and produce ripples that are not in the original.

FADGI explains: "Moiré often occurs upon display of digitized halftone patterns caused by the out-of-phase interaction of the halftone pattern and sensor geometries." Its guidelines add a practical example: "Example – engravings need to be digitized at higher resolutions in order to avoid moiré." The Wikipedia article on moiré patterns notes the same effect when scanning printed pictures.

Our tool has no moiré control, and a text document does not need one: moiré only appears on printed halftone images. If your source already contains a scanned magazine picture, any moiré in it stays visible after processing. A light blur of 0.3–0.4 softens it slightly.

Do edge shadows make a page look scanned?

Edge shadows can make a page look scanned, because a flatbed lid rarely closes perfectly and the gap casts a dark strip along one or two edges. Copiers and feeders can also leave thin dark lines where the paper edge meets the glass. These frame artifacts appear in many real scans, but not all.

Be clear about what our tool does here. It does not draw edge shadows, gradients or lid marks. It offers a Border switch (off by default) that draws a 1-pixel dark line around the page edge. That thin frame imitates the paper edge a copier or feeder picks up, and it suits photocopy looks.

When a page is rotated, the tool fills the exposed corners with white, which matches a scanner with a white lid.

How do the fax look and photocopy look differ?

The fax look and the photocopy look differ mainly in resolution and tone. A fax is coarse, low-resolution and nearly black-and-white, with jagged letter edges. A photocopy is sharper but harsh: whites are blown out, text is dark and thick, and toner speckle or streaks may appear.

What gives a fax its low-resolution look?

A fax looks rough because the standard was designed for phone lines. According to Wikipedia's fax article, Group 3 fax standard resolution is about 200–204 lines per inch horizontally and only 98–100 vertically; the "Fine" mode doubles the vertical resolution to 196–200. A typical Group 3 page takes 6–15 seconds to send.

That uneven, low vertical resolution is why fax text looks stretched and stair-stepped. To imitate it, use the lowest Resolution (1×), Gray colorspace, contrast of 1.5 or more so grays collapse toward black and white, and a little more blur and noise than an office scan.

What gives a photocopy its harsh look?

A photocopy is a copy of a scan printed with toner, so it shows imperfections from two machines. The Wikipedia photocopier article notes that copiers can be identified by imperfections in their output, and that mechanical tolerances in toner and paper feed cause banding.

Copiers can also change content, not just appearance. BBC News reported in 2013 that some office copiers altered digits in scans because of lossy pattern-matching compression (JBIG2): "In his tests, Mr Kriesel found that often the number "6" would be turned into an "8", and vice versa, with other numbers being affected too." Our tool does not use that kind of compression; it only changes appearance, never characters.

To imitate a photocopy, raise contrast to 1.3–1.5, raise brightness to 1.05–1.1 to bleach the paper, keep Gray, add noise around 0.15, and switch the Border on for a thin edge line.

Scan effect cheat sheet: which control does what?

The scan effect cheat sheet below maps each real scanner artifact to its physical cause, to the matching control in our tool, and to the range that still looks natural. Use it as a quick reference when a result looks off: find the artifact that feels wrong and adjust only that control.

Scan effect settings for 5 looks

The five scan effect recipes below are our recommended starting points for the most common looks: office scan, photocopy, fax-like, aged paper and phone scan. Each uses only real sliders from our tool. Enter the values, check the live preview, then adjust one control at a time.

These values are our suggestions, not measured standards. When to use each look:

Office scan

The everyday flatbed or feeder scan. Close to the tool defaults; right for contracts, letters, forms and most documents people expect to receive "as a scan".

Photocopy

Bright paper, dark text, a thin edge line. Suits documents that should look copied several times, such as handouts or old internal memos.

Fax-like

Coarse 1× resolution and high contrast. Suits props, retro designs and forms that traditionally arrive by fax. Keep body text at 10 pt or larger, or it becomes hard to read.

Aged paper

Color mode with a warm sepia tone and slightly lower brightness. Suits archival-style handouts, game props, history projects and vintage designs.

Phone-scan look

A larger, less even tilt and color capture, as if a phone scanner app photographed the page by hand. Suits receipts and one-page documents.

How to apply a scan effect preset step by step

To apply a scan effect preset, open our free web tool, load your PDF or image, enter the recipe values in the settings panel, compare the live preview with the original, and download the scanned PDF. The whole process runs in your browser and usually takes under a minute for a short document.

1. Prepare a PDF. Export Word, Google Docs or spreadsheet files to PDF first (for example File → Download → PDF document in Google Docs). The tool accepts DOCX directly but keeps only its text, so exporting to PDF preserves your layout.
2. Open the tool. Go to pdflookscanned.com/scan and drop the PDF, JPG or PNG into the upload area. Nothing is uploaded to a server; processing happens locally.
3. Choose a look. Pick one of the five recipes above, for example the office scan: rotate 1, variance 0.5, blur 0.3, noise 0.1.
4. Set colorspace and resolution. Select Gray or Color and the Resolution scale (2× for most looks, 1× for fax, 2.5× for the phone look).
5. Adjust tone. Set brightness, contrast and yellowish to the recipe values; switch the Border on only for the photocopy look.
6. Check the preview. Zoom to 100% on a page with small print. If text is hard to read, lower blur first, then contrast.
7. Download and verify. Download the PDF, open it in your viewer and scroll through all pages to confirm each has a slightly different tilt.

For many files at once, the bulk page at /scan/bulk applies the same settings to each file and downloads everything as a ZIP. Image inputs become one single-page PDF each, as explained in our guide to turning an image into a scanned PDF.

What makes a scan effect look fake?

A scan effect looks fake when it is overdone or too uniform: a page rotated 5° or more, the same tilt on every page, heavy blur that smears text, strong noise over a nearly blank page, or margins that stay pure digital white. Real scans are imperfect in small, uneven ways.

Over-rotation

Office scans rarely exceed 2°. Keep Rotate at 0.5–1.5° unless you want the phone look, and stay under 3° even then.

Identical tilt

Every page at exactly the same angle reads as a filter. Keep Rotate variance above 0, ideally 0.3–1°.

Heavy blur

Blur above 0.6 makes small print unreadable, which a working office scanner would not do. Stay at 0.2–0.4.

Noise on white-only pages

Noise covers the whole page, so on a nearly empty page the texture becomes the main thing you see. For sparse pages, lower Noise to 0.05–0.08.

Pure digital white

Paper is never RGB 255 white. A brightness of 0.97–0.99 or a yellowish value of 0.05–0.15 removes the clinical white.

Vector-sharp logos

If a page mixes a soft scan with a crisp pasted signature image, the contrast gives it away. Add stamps or signatures in the tool before processing so they receive the same effect.

A useful test is to put your output next to a real scan from your own office scanner or phone. Compare the gray of the margins, the edge of a small letter at 100% zoom, and the tilt of three different pages. If one of these differs clearly, adjust that single control. The same principle runs through our pillar guide on how to make a PDF look scanned.

When is a scanned look appropriate?

A scanned look is appropriate when you need a document to match the format people expect, such as a paper-style copy for records, a consistent packet of pages, a design or prop, or a flattened file that is harder to edit casually. The scanned look changes appearance only, never what a document proves.

The accessibility trade-off is also real. A scanned-look PDF is made of images, so screen readers cannot read its text unless OCR is added. If a document must be accessible or searchable, keep the original digital PDF alongside the scanned-look copy.

Scan effect FAQ

These scan effect questions come up most often when people try to make a PDF or image look scanned. Each answer is short and self-contained, and the values refer to the real controls in our free tool, which works on desktop browsers, mobile browsers and as a Chrome extension.