What is a Barcode?
History, Tech & Standards
A barcode is an optical, machine-readable representation of data. From the first patent inspired by Morse Code in 1952 to the modern global supply chain, barcodes remain the most cost-effective way to bridge physical products with digital databases.
Inspired by Morse Code
The barcode was invented in 1952 by Norman Joseph Woodland and Bernard Silver. Woodland famously drew lines in the sand at the beach, extending the dots and dashes of Morse Code vertically to create the first linear symbology.
While the first patent was filed in the 50s, it wasn't until June 1974 that the technology hit the mainstream, when a pack of Wrigley's Juicy Fruit gum was scanned at a Marsh Supermarket in Ohio.
Historical Timeline
How a Barcode "Speaks"
A standard 1D barcode represents data by varying the widths and spacings of parallel lines. It is an optical machine-readable language.
Reflection Principle
Scanners measure the light reflected back from white spaces, not the black bars.
The Check Digit
The final number in a code is a mathematical calculation that verifies the scan is accurate.
Standard 1D UPC-A Structure
Common Barcode Symbologies
UPC / EAN
The standard for retail products worldwide. UPC is used in the US; EAN is the international equivalent.
Code 128
A high-density barcode used in logistics and shipping. It can encode all 128 characters of ASCII.
ITF-14
The "Interleaved 2 of 5" code used on corrugated shipping cartons. Designed to be read on rough materials.
Beyond the Checkout Counter
Retail & E-commerce
Instant price updates and efficient POS checkout processing.
Healthcare
Patient identification and precision medication tracking.
Logistics
Real-time tracking of shipments across global supply chains.
Libraries
Managing student IDs and digital resource lending systems.
Manufacturing
Identifying raw materials and monitoring production stages.
Event Management
Secure ticketing and access control for fraud prevention.
Professional Printing Standards
High Resolution
Always print at a minimum of 300 DPI. Low-resolution prints cause "bleeding" between bars, leading to scan failures.
Contrast Ratio
Scanners measure reflected light. Black bars on a white background provide the highest reliability.
Quiet Zones
Every barcode requires a mandatory blank "Quiet Zone" on either side to tell the scanner where the data begins.
Vector Formats
Use SVG or PDF formats for labels to ensure lines remain perfectly crisp regardless of print size.
Barcodes vs. QR Codes
While barcodes are excellent for simple product IDs, they hit a "data ceiling". QR codes were invented to solve this by adding a second dimension.
1D Barcode
Stores ~20 characters. Linear scan only. Best for inventory.
2D (QR Code)
Stores 7,000+ characters. Horizontal & vertical scan. Best for digital experiences.
Frequently Asked Questions
Can I scan a standard barcode with my smartphone?↓
Yes. Most modern iPhone and Android cameras can recognize 1D barcodes automatically. For older devices, there are numerous free apps that use the camera's lens to read the optical pattern and translate it into digital text.
What is the difference between UPC and EAN?↓
UPC (Universal Product Code) is the standard 12-digit barcode used primarily in the United States and Canada. EAN (European Article Number) is a 13-digit version used internationally. Most modern scanners can read both interchangeably.
How much data can a 1D barcode hold?↓
Standard 1D barcodes typically hold between 20 to 25 characters of data. Because they are linear, adding more data makes the barcode physically wider, which eventually makes it difficult for standard laser scanners to read.
What is a 'Check Digit' in a barcode?↓
A check digit is the final number on the right of a barcode. It is the result of a mathematical algorithm based on the preceding numbers, allowing the scanner to verify that the data was read correctly and not distorted.
Why is my barcode not scanning?↓
The most common reasons for scan failure are low contrast (e.g., red bars on a white background), insufficient 'Quiet Zones' (blank space on the sides), or low print resolution (less than 300 DPI) causing the bars to bleed together.
Ready to generate?
Whether you need a legacy barcode or a modern high-capacity QR code, Symbolify provides the professional vector assets you need for production.