QR code print size: how big, how far, contrast, margins and materials

As a rough rule, make the QR code at least a tenth as wide as the distance people will scan from, keep a blank margin of at least four modules around it, print dark on light, keep glossy finishes away from the code, and test one printed sample at the real distance before a large run. If the code has to be small, use a sparse pattern: the denser the pattern, the larger it must be printed.

Size and scanning distance

The one-in-ten ratio is an easy-to-remember rule of thumb, not a figure from the standard. Use it as a starting point and then test. These examples measure the pattern only, without the margin:

• Business card held in the hand, about 20 cm away: about 2 cm
• Table tent read by a seated guest, about 30 cm away: about 3 cm
• Wall poster read standing, about 1 m away: about 10 cm
• Shop front or event sign, about 2 m away: about 20 cm

DENSO WAVE, which invented the QR code, recommends printing codes as large as the available space allows, because larger modules read more easily and reliably (module size).

Denser patterns need more size

A QR code is made of small squares called modules. The more data it holds, the more modules it needs, from 21×21 up to 177×177 (information capacity and versions). Printed in the same space, each module gets smaller. Some examples at error correction level M, the most commonly used level:

• A 26-character short link, such as a qrfast dynamic code: 25×25
• A full Google Form link of about 100 characters: 41×41
• A static vCard with name, title, company, phone, email, website and address: about 65×65

Printed 2 cm wide, those modules measure about 0.8 mm, 0.5 mm and 0.3 mm. A dynamic code stores only a short link, so its pattern stays sparse and can be printed smaller. When you add a logo, qrfast raises error correction to level H automatically, which makes the pattern 33×33, still sparse. The trade-offs between the two kinds are covered in dynamic vs static QR codes.

The quiet zone

The QR code standard (ISO/IEC 18004) requires a blank margin four modules wide on every side, with nothing printed in it: no text, borders or patterns (DENSO WAVE on the code area). Measure it from the edge of the pattern, not the edge of the image file, because the white border included in an image may be narrower than four modules, so add space in your layout. For a 2 cm code with 25×25 modules, four modules is about 3 mm per side.

Color and contrast

• Print dark modules on a light background; black on white gives the highest contrast. Brand colors work if the pattern is clearly darker than the background, such as dark brown or navy on white or cream.
• Avoid light modules on a dark background (inverted colors). Some scanning apps cannot read them; if you must use them, test on several phones first.
• Gradients are fine as long as the lightest part of the pattern is still clearly darker than the background.
• Keep the background plain. Over a photo or pattern, put the code in a white box that includes the margin.
• If you download with a transparent background, make sure the surface it goes on is light and plain.

Materials and surfaces

• Glossy surfaces such as gloss lamination, acrylic or shiny vinyl stickers reflect lights and can wash out parts of the pattern in the camera image. Use a matte finish over the code, or place it where lights do not shine straight at it.
• Curved surfaces such as cups, bottles and pillars distort the pattern; the larger the code relative to the curve, the harder it is to read. Test from the angle people will actually use.
• Absorbent materials such as rough paper or fabric let ink spread so modules bleed into each other. Use a sparser code and print it larger.
• Outdoors, sunlight fades ink and lowers contrast. Choose fade-resistant materials and inks, and rescan the sign from time to time.

Logos and stickers on top

QR codes have four built-in error correction levels. Higher levels survive more damage or covering but make the pattern denser (DENSO WAVE on error correction). When you add a logo in the qrfast builder, error correction switches to level H automatically. A logo, sticker or price label stuck on top after printing gets no such allowance and may cover vital parts such as the three large corner squares. Add logos when you create the code, and test every time.

Files and the A4 print sheet

• Send SVG to a print shop; it stays sharp at any size.
• If you must use PNG, download 2048 px. At 300 dpi that prints about 17 cm wide; for anything larger, use SVG.
• Never stretch the image so that its width and height differ.
• JPG compression can blur the edges of modules; for print, choose SVG or PNG.

To print on an office printer, the qrfast builder has an A4 print sheet option under the preview: 1 sign, 4 table cards or 12 stickers, with codes 14 cm, 7.5 cm and 4.5 cm wide. By the one-in-ten rule they suit scanning from about 1.4 m, 75 cm and 45 cm.

1. Create the code and set the caption you want; the sheet prints it under every code.
2. Choose a layout under A4 print sheet and press Print. The browser's print dialog opens: pick your printer, or choose "Save as PDF" to send a file to a print shop.
3. Set the paper to A4 with no scaling so the codes come out at the size you chose, then measure the first sheet with a ruler.
4. Cut along the dashed lines. The sheet is plain, with no qrfast frame or logo.

Test before a large print run

1. Print one sample on the real material at the real size.
2. Scan it from the distance and angle people will use, under the actual lighting.
3. Use at least two phones, an iPhone and an Android, with their normal camera apps.
4. Check that it reaches the right destination.
5. If it scans poorly, change one thing at a time: a larger code, a wider margin, more contrast or a different surface.

If you find a wrong destination after printing, a dynamic code can be fixed from the manage link without reprinting. Problems with size, margin or contrast can only be fixed by reprinting.

FAQ

What is the smallest size I can print?

There is no single number for every job. It depends on how many modules the pattern has, print quality and the scanner's camera. Use a sparse code, keep the full margin and test a print at the size you need.