UPC-A

UPC-A (Universal Product Code) is the standard barcode format for retail products in North America. It consists of 12 digits and is technically a subset of EAN-13 (with a leading zero).

Basic Usage

import { barcode } from '@stacksjs/qrx'

barcode('#barcode', '123456789012', { format: 'UPC' })

[!NOTE] Image needed: Basic UPC-A barcode example

Structure

A UPC-A barcode consists of:

• First digit: Number system digit
• Next 5 digits: Manufacturer code
• Next 5 digits: Product code
• Last digit: Check digit (automatically calculated)

Auto Check Digit

The check digit is automatically calculated if omitted:

import { barcode } from '@stacksjs/qrx'

// These generate the same barcode
barcode('#barcode', '12345678901', { format: 'UPC' })   // Auto-calculates check digit
barcode('#barcode', '123456789012', { format: 'UPC' })  // Manual check digit

Flat Mode

Remove guard bars for special applications:

import { barcode } from '@stacksjs/qrx'

barcode('#barcode', '123456789012', {
  format: 'UPC',
  flat: true
})

[!NOTE] Image needed: UPC-A flat mode example

Advanced Options

import { barcode } from '@stacksjs/qrx'

barcode('#barcode', '123456789012', {
  format: 'UPC',
  width: 2,
  height: 100,
  displayValue: true,
  font: 'OCRB',
  fontSize: 18,
  textMargin: 0,
  flat: false,
  guardHeight: 15  // Height of guard bars
})

Guarded Encoding

The standard way of printing UPC-A with guard bars:

import { barcode } from '@stacksjs/qrx'

barcode('#barcode', '123456789012', {
  format: 'UPC',
  guardHeight: 15
})

[!NOTE] Image needed: Example showing guard bars

Add-on Support

Combine with EAN-2 or EAN-5 supplemental barcodes:

import { barcode } from '@stacksjs/qrx'

barcode('#barcode')
  .UPC('123456789012')
  .blank(20)
  .EAN5('12345', {
    height: 85,
    textPosition: 'top'
  })
  .render()

[!NOTE] Image needed: UPC-A with add-on example

Number System Digits

The first digit has special meaning:

• 0: Regular UPC codes
• 1: Reserved
• 2: Weight items marked at the store
• 3: National Drug Code/Health Related
• 4: Non-food items with no code format restrictions
• 5: Coupons
• 6: Reserved
• 7: Regular UPC codes
• 8: Reserved
• 9: Reserved

// Example of a pharmaceutical product
barcode('#barcode', '312345678912', { format: 'UPC' })

// Example of a weighted item
barcode('#barcode', '212345678912', { format: 'UPC' })

Error Handling

import { barcode } from '@stacksjs/qrx'

barcode('#barcode', '123456789012', {
  format: 'UPC',
  valid: (valid) => {
    if (!valid) {
      console.error('Invalid UPC-A')
      // Handle invalid input
    }
  }
})

Best Practices

1. Input Validation

   • Validate length (11-12 digits)
   • Verify number system digit
   • Check manufacturer code validity

2. Printing Guidelines

   • Minimum size requirements
   • Quiet zone specifications
   • Print quality standards

3. Scanner Compatibility

   • Test with multiple scanners
   • Verify add-on compatibility
   • Check guard bar recognition

Technical Notes

1. Size Requirements

   • Nominal size: 37.29mm × 25.91mm
   • Magnification range: 80% to 200%
   • Minimum bar width: 0.264mm
   • Minimum quiet zone: 9mm

2. Conversion to EAN-13

   // UPC-A
   barcode('#barcode', '123456789012', { format: 'UPC' })
   
   // Equivalent EAN-13
   barcode('#barcode', '0123456789012', { format: 'EAN13' })

[!NOTE] Image needed: Technical specifications diagram

Common Applications

1. Retail Products

   • Consumer goods
   • Point of sale scanning
   • Inventory management

2. Grocery Items

   • Fixed weight products
   • Variable weight items
   • In-store marked items

3. Healthcare Products

   • Pharmaceuticals
   • Medical supplies
   • Health-related items

[!NOTE] Image needed: Real-world application examples