<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[Printing & scanning]]></title><description><![CDATA[Sizes, materials, contrast, quiet zones — why a code scans on screen but not on a sticker.]]></description><link>https://qrcodestack.com/community/category/5</link><generator>RSS for Node</generator><lastBuildDate>Sun, 30 Aug 2026 14:36:27 GMT</lastBuildDate><atom:link href="https://qrcodestack.com/community/category/5.rss" rel="self" type="application/rss+xml"/><pubDate>Sat, 29 Aug 2026 15:10:19 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[Why a QR code scans on screen but fails once printed]]></title><description><![CDATA[A code that works on your monitor and fails on card is almost always one of these five.
1. Not enough contrast. Cameras read light and dark, not colour. Dark-on-light with a real difference in brightness works; mid-grey on beige does not, however good it looks in the mockup. If you are unsure, photograph the printed code in black and white — if you can barely see the pattern, neither can a phone.
2. Inverted colours. Light code on a dark background fails on a meaningful share of scanners. Some read it, some do not, and you will not know which your customers carry.
3. The quiet zone was trimmed. The clear margin around the code is part of the code. Layouts routinely eat it.
4. Gloss and lamination. A glossy laminate under a downlight throws a highlight straight back at the lens. Matte finish is worth the small extra cost anywhere the code sits under direct light.
5. Too much data crammed in. The more you encode, the more modules, the finer each one, the worse it survives ink spread. Pointing at a short URL instead of a long one with tracking parameters attached is the single easiest fix.
Error correction is not a free pass
Higher error correction lets a code survive damage — a logo in the middle, a scuff, a fold. It does this by adding redundancy, which means more modules in the same space. Turning it up to survive a logo can make a small code harder to scan, not easier. If you are placing a logo, grow the code at the same time.
When it is already printed
If a run is out in the world and scanning badly, a dynamic code is the difference between a reprint and an afternoon: the destination can be changed without touching the artwork. A static code cannot — the destination is baked into the pattern itself. That is the main reason to prefer dynamic for anything that gets printed in volume.
]]></description><link>https://qrcodestack.com/community/topic/3/why-a-qr-code-scans-on-screen-but-fails-once-printed</link><guid isPermaLink="true">https://qrcodestack.com/community/topic/3/why-a-qr-code-scans-on-screen-but-fails-once-printed</guid><dc:creator><![CDATA[admin]]></dc:creator><pubDate>Sat, 29 Aug 2026 15:10:19 GMT</pubDate></item><item><title><![CDATA[What size should a QR code sticker be?]]></title><description><![CDATA[The short answer is a ratio, not a number: the code should be about one tenth of the distance it will be scanned from.

Scanned from 30 cm (a table tent, a business card): 3 cm minimum
Scanned from 1 m (a shop window, a counter sign): 10 cm
Scanned from 3 m (a wall poster): 30 cm
Scanned from 10 m (a banner, a vehicle): 1 m

Treat those as floors, not targets. A code that is comfortably too big costs nothing; one that is 15% too small fails silently and you never hear about it.
The three things that break a technically correct size
The quiet zone. A QR code needs clear space around it — roughly four modules' worth, where a module is one of the little squares. Designers trim it constantly to fit a layout. A code with artwork crowding its edge fails at any size.
Module size after printing. What matters physically is how big one module ends up. Below roughly 0.5 mm per module, ink spread on absorbent stock starts merging neighbouring modules. If your code encodes a lot of data it has more, smaller modules at the same overall size — which is one practical reason to point a code at a short URL rather than a long one.
The surface. Curved bottles, textured card, anything laminated glossy under a shop light. Curvature distorts the grid; gloss throws back the light the camera needs. On a curved surface, go a size up and keep the code away from the steepest part of the curve.
Test it the way a customer will
Print one, at final size, on the final material. Then scan it: at the real distance, at an angle, in the actual lighting, on the oldest phone in the office. A code that works on your desk under a lamp tells you nothing about a rainy Tuesday outside a café.
If you are printing a run of thousands, the ten minutes this takes is the cheapest insurance available.
]]></description><link>https://qrcodestack.com/community/topic/2/what-size-should-a-qr-code-sticker-be</link><guid isPermaLink="true">https://qrcodestack.com/community/topic/2/what-size-should-a-qr-code-sticker-be</guid><dc:creator><![CDATA[admin]]></dc:creator><pubDate>Sat, 29 Aug 2026 15:10:19 GMT</pubDate></item></channel></rss>