Frequently Asked Questions
Find answers regarding direct thermal technology, courier 4x6 compatibility, roll cores, and business orders.
All FAQ Answers
What are direct thermal labels? +
Direct thermal labels are paper rolls coated with a heat-sensitive layer. When passed through a direct thermal printer, heat from the printhead creates high-contrast black text, barcodes, and graphics without ink, toner, or ribbon.
Do thermal labels need ink? +
No. Direct thermal labels require zero ink, toner, or printer ribbons. The printing mechanism is entirely heat-based.
What is a 4x6 thermal shipping label? +
A 4x6 thermal shipping label measures 4 inches wide by 6 inches high (100mm x 150mm). It is the standard official shipping label format required by Royal Mail, DPD, Evri, Amazon, and DHL.
Are 4x6 labels the exact same as 100x150mm labels? +
Yes. 4x6 inches converts to 101.6mm x 152.4mm, which is rounded to 100x150mm in UK metric shipping specifications.
Which printers use thermal labels? +
Thermal desktop printers manufactured by Zebra (ZD421, ZD420, GX420), Rollo Wireless, Munbyn (ITPP941), Brother (TD-4410D, QL-1110NWB), Dymo (LabelWriter 4XL/5XL), and Phomemo (PM-246) use direct thermal label rolls.
Which labels work with Zebra thermal printers? +
Zebra desktop printers (such as ZD421, ZD420, GX420d, GK420d) use standard 4x6 inch (100x150mm) direct thermal label rolls on a 25mm (1 inch) cardboard core. No ink ribbon is required for ZD direct thermal models.
Which labels work with Rollo thermal printers? +
Rollo Wireless and USB desktop printers work with standard 4x6 inch (100x150mm) direct thermal label rolls on 25mm cores, as well as fanfold thermal labels. They print completely inklessly at high speeds.
How long do direct thermal labels last before fading? +
Top-coated direct thermal labels last up to 1-2 years under standard UK indoor archive and parcel shipping conditions. Avoiding direct sunlight, high heat, and chemical solvent exposure prevents premature image fading.
What is the difference between direct thermal and thermal transfer? +
Direct thermal prints directly onto heat-sensitive paper without ink or ribbon (ideal for shipping & ecommerce). Thermal transfer uses a heated ink ribbon to print onto plain paper or synthetic labels (ideal for long-term outdoor or chemical tagging).
How do I know which label fits my printer? +
Check two specifications: 1) Maximum print width (usually 4 inches / 104mm for shipping printers) and 2) Core diameter (standard 25mm / 1 inch for desktop printers). Use our interactive 'Find My Label' tool to verify fit instantly.
How many labels are on a roll? +
Our standard desktop 4x6 rolls contain 500 labels per roll (25mm core). High-capacity commercial rolls contain 1,000 labels per roll (38mm core).
Can I buy thermal labels in bulk for business? +
Yes. ThermalLabelUK provides wholesale tiered pricing starting from 5 rolls up to full pallet quantities. You can request a custom bulk quote online.
Do you supply UK business accounts? +
Yes. We supply ecommerce merchants, 3PL warehouses, dispatch hubs, and retail businesses across the UK with invoice billing options and bulk dispatch.
Can I easily reorder the same labels? +
Yes. Use our quick 'Reorder' feature or customer reference SKU to order repeat supplies with identical specifications.