QR & Barcodes
Practical ideas for better decisions, from content creation to everyday digital work.
Can You Change a QR Code's Color? (Light Colors and Transparent Backgrounds Tested in Blurry, Dim Photos)
I made QR codes in 9 colors and with transparent backgrounds, decoded 100 simulated phone captures of each, and compared recognition in normal, blurry and dim conditions.
2026-10-17
CODE128 vs CODE39 (Inventory and Asset Labels: How Long Is the Same Barcode?)
I encoded the same values in CODE128 and CODE39 to compare printed length, accepted characters and decoding—and how many characters fit on a 50mm label.
2026-10-14
How to Make a Wi-Fi QR Code (Do Special Characters Work? Plus Print Size)
I made 9 Wi-Fi QR codes—special characters, Korean, spaces, hidden networks—decoded them, and worked out print sizes by password length.
2026-10-12
Barcode Print Size: How Many Millimeters? (EAN-13 at 80–200%, Measured)
What size should a product barcode be when you print it yourself? I compared the GS1 EAN-13 spec with the actual size at each magnification and checked whether PNG, SVG and PDF files keep that size in a document.
2026-10-01
QR Code Print Size: How Many Centimeters? (Minimum Size by URL Length and Scanning Distance)
How large should you print a QR code on a flyer or business card? I made QR codes for three URLs of different lengths, ran a scan test, and summarized minimum sizes by distance plus how colors and transparent backgrounds affect scanning.
2026-09-29