Complete Guide to Barcode Labels: Sizes, Materials & Templates

Understanding Barcode Labels

Barcode labels are the small stickers you see on every product in a supermarket. They contain a scannable barcode, the product name, and usually the price. Choosing the right label size and material directly affects how professional your shop looks and how smoothly your checkout runs.

Common Label Sizes Used in Sri Lanka

For most Sri Lankan retail shops, 30x20mm or 40x30mm labels are the standard choice. These are small enough to fit on most products but large enough for a barcode and price to be clearly scannable.

Label Materials

Direct Thermal Labels

The most common choice for retail. These labels are heat-sensitive — the printer uses a heated print head to create the image directly on the label surface. No ink or ribbon needed.

Pros:

• Cheapest to operate (no ribbon cost)
• Simple — just load the roll and print
• Available everywhere in Sri Lanka

Cons:

• Fade over time (6–12 months), especially in heat
• Not suitable for products stored in hot environments
• Can darken if exposed to sunlight

Best for: Price tags, shelf labels, checkout receipts — anything that doesn’t need to last more than a few months.

Thermal Transfer Labels

These use a ribbon (an ink film) that transfers onto the label when heated. The result is a permanent, durable print.

Pros:

• Extremely durable — lasts years
• Resistant to heat, moisture, chemicals
• Works on various materials (paper, synthetic, polyester)

Cons:

• Requires ribbon (additional cost)
• Slightly more complex to set up
• Ribbon changes add maintenance time

Best for: Permanent asset tags, outdoor labels, chemical product labels, manufacturer barcodes.

Paper Labels (for Inkjet/Laser Printers)

A4 sheets with pre-cut label grids. You print using a regular office printer.

Pros:

• No special printer needed
• Good for occasional use

Cons:

• Slow and wasteful for high volumes
• Less precise barcode quality
• Individual labels harder to peel

Best for: Shops that print fewer than 20 labels per week and don’t want to invest in a thermal printer.

Label Roll Specifications

When buying label rolls, you need to know three numbers:

1. Label size — width x height in mm (e.g., 40x30mm)
2. Core size — the inner cardboard tube diameter (usually 25mm or 40mm). Check what your printer supports.
3. Labels per roll — typically 500–2,000 depending on label size

Most printers sold by Invenova use 25mm core rolls. When ordering replacement labels, always specify your core size.

Where to Buy Label Rolls in Sri Lanka

Label rolls are available from:

• Invenova — we sell compatible label rolls for all printers in our catalog. WhatsApp us to order.
• Daraz — search for “thermal label roll” + your size
• Local stationery suppliers — shops in Pettah (Colombo) carry bulk thermal label stock

Tip: When buying from Daraz or local suppliers, always ask for “top-coated direct thermal” labels. Uncoated labels produce faint prints and fade faster.

Designing Your Labels with Invenova

Invenova’s free barcode printing tool includes built-in label templates:

• Price tag template — barcode + product name + price
• Product label template — barcode + product name + price + description
• Shelf label template — large price with barcode for shelf edges
• Custom template — design your own layout with your shop logo

You can customize fonts, sizes, and positions. The tool automatically formats the barcode to be scannable at the size you choose.

Label Printing Best Practices

1. Always calibrate when changing label sizes. Most printers have an auto-calibration function (hold the feed button for 3 seconds). Invenova’s Print Agent does this automatically.

2. Store label rolls in a cool, dry place. Heat and humidity cause thermal labels to darken prematurely. Keep unused rolls wrapped in their original packaging.

3. Use labels within 12 months of purchase. Direct thermal labels have a shelf life. Old labels may not print clearly.

4. Test one label before printing a batch. Print a single label first to verify alignment and quality before committing to a large print job.

5. Clean the print head monthly. Use an isopropyl alcohol wipe on the print head to remove residue. This prevents streaks and extends the printer’s life.

Getting Started

The simplest way to start is to:

1. Order a printer from Invenova (we include a sample label roll)
2. Sign up for the free barcode tool
3. Add your products and print your first labels

We’ll help you set everything up via WhatsApp — completely free.