vretti 420B-WIFI
vretti Wi-Fi Thermal Label Printer User Manual
Model: 420B-WIFI | Brand: vretti
1. Introduction

Figure 1.1: vretti Wi-Fi Thermal Label Printer.
This user manual provides detailed instructions for the setup, operation, and maintenance of your vretti Wi-Fi Thermal Label Printer. Please read this manual thoroughly before using the printer to ensure proper functionality and to extend the product's lifespan. This printer is designed for efficient printing of shipping labels, warehouse labels, barcode and ID labels, and package labels.
2. Safety Information
- Ensure the printer is placed on a stable, flat surface.
- Do not expose the printer to water or excessive humidity.
- Use only the provided power adapter and cable.
- Keep the printer away from heat sources and direct sunlight.
- Do not attempt to disassemble or repair the printer yourself. Refer to qualified service personnel.
- Unplug the printer from the power outlet before cleaning or if it will not be used for an extended period.
3. Package Contents
Verify that all items listed below are included in your package:
- 1 x vretti Wi-Fi Thermal Label Printer
- 1 x Power Adapter
- 1 x Power Cord
- 1 x USB Cable
- 1 x U Disk (containing drivers and how-to videos)
- 1 x Paper Roll Shaft
- 2 x Fixing Plates
- 1 x User Manual

Figure 3.1: Contents included in the vretti thermal label printer package.
4. Setup Guide
4.1 Loading Labels
The vretti thermal label printer features a built-in label bin designed to accommodate various label types, including roll and fanfold labels. It supports label widths from 25.4mm (1 inch) to 115mm (4.5 inches), with a maximum print width of 108mm (4.25 inches).
- Open the top cover of the printer.
- Place the label roll onto the paper roll shaft and secure it with the fixing plates.
- Feed the labels through the adjustable guide rail, ensuring they are aligned properly. The guide rail can be adjusted to fit label widths between 0.78 and 4.6 inches.
- Close the top cover.

Figure 4.1: Built-in large label bin with adjustable guide rail.

Figure 4.2: Adjusting label width for various label sizes.
4.2 Power Connection
Connect the power adapter to the printer and then plug the power cord into a suitable electrical outlet.
4.3 Connectivity Options
Your vretti printer supports both USB and Wi-Fi connections for versatile printing.
4.3.1 USB Connection
The printer can be connected to Windows, Mac, and Linux systems via USB. Ensure the printer is connected and turned on before driver installation.
- Connect the provided USB cable from the printer to your computer.
- Install the necessary drivers from the included U Disk or download them from the official vretti website.
- For Mac users: If you encounter an "The application can't be opened" message during driver installation, navigate to "System Settings" > "Privacy & Security", scroll down, and click "Open Anyway" to allow the installation.
4.3.2 Wi-Fi Connection
The vretti Wi-Fi Thermal Label Printer supports 2.4GHz Wi-Fi networks only. It does not support 5GHz networks.
- Ensure your device (Windows, MacOS, iOS, Android) is connected to a 2.4GHz Wi-Fi network.
- Download the "wireless link" app to obtain the printer's IP address.
- Use the "Ezlabel" app (for iOS/Android) or "4barcode" app (for general use) to connect and initiate printing. You may need to enter the IP address obtained from the "wireless link" app.

Figure 4.3: Wi-Fi printing setup for smartphones.

Figure 4.4: Printer connectivity via Wi-Fi and USB.
5. Operating Instructions
5.1 Printing Labels
The vretti thermal label printer is compatible with a wide range of e-commerce and shipping platforms, including Amazon, eBay, Shopify, USPS, UPS, Etsy, PayPal, Poshmark, Pirate Ship, and Canada Post.
- Ensure the printer is powered on and connected via USB or Wi-Fi.
- Prepare your label file on your computer or mobile device.
- For Wi-Fi printing: Download the label to be printed from your platform, then upload it to the "4barcode" editor app for printing.
- Select the vretti printer from your device's print options.
- Adjust print settings (e.g., paper size, darkness) as needed.
- Initiate the print job. The printer offers high-speed printing at up to 152mm (6 inches) per second.

Figure 5.1: Wide compatibility with multiple platforms and labels.

Figure 5.2: Clear and high-speed printing performance.
6. Maintenance
Regular maintenance ensures optimal performance and extends the life of your thermal label printer. Since it is a thermal printer, no ink or TTR ribbons are required, simplifying maintenance.

Figure 6.1: Ink-free and cartridge-free operation.
6.1 Cleaning the Print Head
The print head is a critical component and should be cleaned periodically to prevent print quality issues.
- Turn off the printer and unplug the power cord.
- Open the top cover to access the print head.
- Gently wipe the print head with a cotton swab lightly dampened with isopropyl alcohol. Allow it to dry completely before closing the cover and powering on the printer.
6.2 General Cleaning
Wipe the exterior of the printer with a soft, dry cloth. Do not use abrasive cleaners or solvents.
7. Troubleshooting
This section addresses common issues you might encounter with your vretti thermal label printer.
7.1 Printer Not Responding / Not Printing
- Check Power: Ensure the printer is properly connected to a power source and turned on.
- Check Connection: Verify that the USB cable is securely connected to both the printer and the computer, or that the Wi-Fi connection is active and stable.
- Driver Installation: Confirm that the correct printer drivers are installed on your computer. Reinstall if necessary.
- Label Loading: Ensure labels are loaded correctly and not jammed.
7.2 Wi-Fi Connectivity Issues
- 2.4GHz Network: The printer only supports 2.4GHz Wi-Fi networks. Ensure your router is configured for 2.4GHz or that your device is connected to the 2.4GHz band. It does not support 5GHz networks.
- IP Address: Use the "wireless link" app to confirm the printer's IP address. Ensure this IP is correctly entered into the "Ezlabel" or "4barcode" app.
- Network Stability: A weak or unstable Wi-Fi signal can cause connection drops. Ensure the printer is within range of your router.
- Router Settings: Some router settings (e.g., firewall, WPA3 encryption) might interfere with connectivity. Consult your router's manual or IT support if issues persist.
7.3 Poor Print Quality
- Clean Print Head: A dirty print head can cause faded or streaky prints. Refer to Section 6.1 for cleaning instructions.
- Label Quality: Ensure you are using high-quality direct thermal labels.
- Print Darkness: Adjust the print darkness settings in your printer driver or application.
7.4 Printer Stops Printing Mid-Job (Red Light Blinking Fast)
This can indicate a temporary error or a communication issue.
- Restart Printer: Turn off the printer, wait a few minutes, then turn it back on.
- Check Labels: Ensure there are enough labels and no jams.
- Re-establish Connection: If using Wi-Fi, try reconnecting through the app or restarting your router.
8. Specifications
| Feature | Specification |
|---|---|
| Resolution | 203 DPI (203 x 203 DPI) |
| Printing Method | Direct Thermal Printer |
| Max. Print Speed | 152mm (6 inches)/s |
| Max. Print Width | 108mm (4.25 inches) |
| Max. Print Length | 1778mm |
| Printing Language | TSPL, EPL, ZPL, DPL |
| Compatible Systems | Windows (11/10/7/XP), Mac, Linux, Android, iOS |
| Printing Label Type | Roll label and fanfold label |
| Interface | USB + Wi-Fi (2.4GHz only) |
| Media Width | 25.4mm - 115mm (1 inch - 4.5 inches) |
| Media Thickness | 0.06 - 0.254mm (2.36 - 10 mil) |
| Product Dimensions (LxWxH) | 21.5 x 17.8 x 15.5 cm (8.46 x 7.01 x 6.1 inches) |
| Product Weight | 1.31 kg (2.89 lbs) |
| Power Supply | AC 110-240V, DC 24V 2.5A |
| Sensors | Gap Sensor, Cover Opening Sensor, Black Mark Sensor |
9. Warranty and Support
For detailed warranty information and technical support, please refer to the official vretti website or contact their customer service. A digital version of this user manual is available for download at: vretti User Manual (PDF).
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