Label Ninja

Free thermal label tools

What are you printing?

The next parcel, shelf bin, or live show. Pick a job and make a PDF that matches the stock in your printer.

Convert a shipping label Open the custom editor ↗
Shipping label4 × 6 in
Illustrative 4 by 6 inch shipping label; not valid postage
4.00 in6.00 in
Example artwork. Actual aspect ratio; screen size is illustrative.

Built at a real packing table.

I'm Chris, a multichannel reseller who prints thousands of labels. These are the tools and print checks I want within reach.

Free tools · Actual-size PDFs · Print at 100%

A tool for each job.

Free thermal label makers for 4x6 and small labels. Choose your stock, check the preview, then print at Actual size.

From screen to stock.

  1. Pick a tool and label size. Match the size to the roll in your printer.
  2. Fill in your labels. The preview updates as you type; no account needed yet.
  3. Download the PDF. Studio tools need a free account (email and password, no card). The shipping converter needs no account.
  4. Print at 100% scale. Choose the matching paper size, set margins to none, and print one test label before the full run. See the printer setup checklist.

Start with the stock on your desk.

These sizes exist in the tools. The printer's width, feed and label system still need to match. A PDF size alone cannot prove stock compatibility.

4" x 6"
Shipping and bin labels · Rollo, Zebra, Munbyn
4" x 3"
Carton and box inventory
3" x 2"
Whatnot show numbers
2" x 1"
Product / FNSKU labels
2.25" x 1.25"
Custom editor · DYMO 30334 multipurpose
1" x 0.5"
Tiny 25 x 13 mm stock

See all editor presets · Check stock compatibility

Questions

Is Label Ninja free?

Yes. Every tool and every PDF download is free. There is no paid plan and no card to enter.

Do I need an account?

You can design and preview labels without one. Downloading a PDF and saving projects need a free account (email and password), so your PDFs and projects stay with you.

Does the 4x6 shipping label converter upload my label?

No. The shipping label converter runs in your browser, needs no account, and your label file never leaves your device.

Which printers work?

Any printer that can print a PDF at the label's real size. That includes 4-inch direct thermal printers such as Rollo, Zebra, and Munbyn for 4x6 labels, and Dymo LabelWriter-style printers for small rolls.

Why is my label printing too small or cut off?

The print dialog is usually scaling the page. Pick the paper size that matches your label, set scale to 100% or Actual size, and set margins to none. The too-small printing guide walks through it.

Does Label Ninja create FNSKUs or buy postage?

No. The FNSKU tool prints identifiers you already have from Seller Central, and Label Ninja does not sell shipping postage.

How long are my PDFs kept?

A downloaded PDF is yours to keep and reprint. Copies in My Exports can be downloaded again for 7 days.

Warehouse bin labels

One complete 4" x 6" label per bin — the bin number on top, its CODE128 barcode underneath — for Rollo, Zebra, and any 4-inch direct thermal printer.

1 bin = 1 page CODE128 Exact size PDF
Printed before the number
Added after the number
Up to 200 labels per PDF
inches
inches
1 thin – 5 bold
inches
Settings: Unsaved

Whatnot show number labels

Numbered item labels for your next show. Choose a range and stock, then download one PDF. No Whatnot account connection or shipping postage.

Whatnot labels setup and sizes · Fix tiny or cropped prints

1 number = 1 label 3 stocks Exact size PDF
Printed before each number
Up to 200 labels per PDF
Settings: Unsaved

Amazon FNSKU labels

Print an existing FNSKU with the item title, CODE128 barcode and condition on a 2" x 1" label. Copy your identifier from Seller Central; this tool does not issue FNSKUs. UPCs and other single barcode values work too.

2 x 1 in CODE128 Exact size PDF
Copy it from Seller Central (FNSKUs start with X00). UPCs work too.
Short is best on 2" x 1"
Settings: Unsaved
Thermal label printer guides

Set up a label printer for 4x6 shipping, bin, barcode, and FNSKU labels

Start with your label stock, match the PDF and driver sizes, then print one test page at 100% scale. Use these guides to fix small, sideways, blank, or skipped labels before running a batch.

Universal thermal label printer setup checklist

Use this first for Rollo, Zebra, DYMO 4XL, Brother, MUNBYN, Nelko, Polono, Jadens, and most 203 DPI direct thermal printers. It matches the recurring setup pattern shown by official Rollo setup pages, Zebra's ZD421 documentation, DYMO LabelWriter help, and shipping-platform support guides.

  1. Install the real driver before plugging in

    Download the current driver or setup utility from the printer maker. On Windows, this prevents the printer from showing up as a generic USB device. If it already did, unplug it, install the driver, reboot if needed, then reconnect.

  2. Set the exact label size

    For shipping labels use 4" x 6" or the closest driver option, often 100 x 150 mm, 102 x 152 mm, or 4 x 6 in. For small barcode labels use the exact stock size such as 2" x 1", 1" x 0.5", or 3" x 2".

  3. Print at 100% scale with no margins

    In Chrome or the system print dialog, choose Scale 100%, Margins None, and the correct orientation. Do not use Fit to page if your barcode is shrinking, blurring, or printing off-center.

  4. Calibrate after changing label rolls

    If labels skip, feed continuously, stop halfway, or start in the wrong spot, run printer calibration. Zebra calls this SmartCal on ZD421/ZD621 models; other printers usually have a feed-button calibration sequence or setup utility.

Label Ninja print settings that usually work

Warehouse bins: 4" x 6" portrait or 6" x 4" landscape, no margins, 100% scale. Whatnot numbers: choose matching stock in Label Ninja, then choose the same paper size in the driver. FNSKU/barcode labels: start with 2" x 1", 100% scale, and make sure the barcode is not stretched by the print dialog.

Brand setup guides

Rollo printer setup for 4x6 labels

Searches this solves: how to set up Rollo printer, Rollo 4x6 label setup, Rollo printing sideways, Rollo blank labels, Rollo skipping labels.

  1. Install the Rollo wired or wireless setup path from Rollo's setup page.
  2. Set paper size to 4 x 6 in, 100 x 150 mm, or 102 x 152 mm depending on driver.
  3. In Chrome print preview choose the Rollo printer, margins none, and scale 100%.
  4. If the print is sideways, change orientation first before changing Label Ninja layout.
  5. If labels feed wrong, recalibrate from the Rollo utility or feed-button sequence.
Official setup Make bin labels

Zebra ZD421 setup for labels

Searches this solves: Zebra ZD421 setup, Zebra ZD421 label size, Zebra SmartCal, Zebra printer calibration, Zebra ZD421 4x6 labels.

  1. Load media, close the printer, and run SmartCal media calibration.
  2. Install Zebra Setup Utilities or the current Zebra driver before configuring Windows.
  3. Set label width, label length, label type, darkness, and speed in the driver.
  4. Use 203 DPI-friendly barcode sizing unless you specifically own the 300 DPI model.
  5. For web printing, verify Chrome print preview keeps paper size, orientation, and scale at 100%.
Zebra drivers Make FNSKU labels

DYMO LabelWriter setup

Searches this solves: DYMO LabelWriter 450 setup, DYMO 4XL 4x6 shipping labels, DYMO label size, DYMO blank labels, DYMO labels not aligned.

  1. Use DYMO-compatible label rolls and load them from underneath the roll into the guide.
  2. Install DYMO Connect or the correct legacy driver for older LabelWriter models.
  3. Choose the exact DYMO stock code or physical size in printer preferences.
  4. For 4x6 shipping labels, use DYMO 4XL-class hardware rather than small address-label models.
  5. If alignment drifts, reseat the spool tightly and confirm the label guide is snug.
DYMO help Make number labels

Choose a printer for your packing table.

Start with the job and the devices you print from. Check the exact model, stock and current driver support before buying. These are manufacturer specifications and practical selection checks, not hands-on product reviews.

Specifications checked October 5, 2026. Shopping links open Amazon searches; their models, sellers and prices can vary.

Affiliate links: As an Amazon Associate I earn from qualifying purchases. About shopping links.

6 printer choices. Compare exact models, not just brand names.

Shared or mobile packing table

Rollo Wireless X1040

Connection
Wi-Fi / AirPrint + USB
Resolution
203 DPI
Label width
1.57–4.1 in
Feed
Fanfold or external roll

Who it's for: You print from several devices or need phone printing over Wi-Fi.

Skip if: One USB-connected computer already handles all your labels, or your stock falls outside the supported width.

Manufacturer specifications

Check price on Amazon

One computer, one print station

Rollo USB X1038

Connection
USB
Resolution
203 DPI
Label width
1.57–4.1 in
Feed
Fanfold or external roll

Who it's for: You pack at a fixed computer and want a direct USB connection.

Skip if: You need native phone or shared Wi-Fi printing. Leave clearance behind it for the labels.

Model specifications · Stock and feed requirements

Check price on Amazon

Configurable warehouse printer

Zebra ZD421 Direct thermal

Connection
USB; network options vary
Resolution
203 DPI / optional 300 DPI
Max print / media width
104 mm at 203 DPI / 108 mm
Feed
Roll-fed or fanfold

Who it's for: You need adjustable media sensing and a configuration matched to warehouse stock.

Skip if: You want to buy by family name alone. Verify direct thermal versus ribbon-based models and whether Wi-Fi is actually included.

Manufacturer specifications

Check price on Amazon

Existing DYMO roll setup

DYMO LabelWriter 4XL

Connection
USB
Resolution
300 DPI
Max print width
4.16 in / 105.73 mm
Feed
Rolls; fanfold not documented

Who it's for: You already use compatible DYMO rolls and can confirm driver support for your computer.

Skip if: You want to use a generic fanfold stack. This older model's supplies should not be assumed interchangeable with the 5XL.

Manufacturer manual and specifications

Check price on Amazon

Compare an exact MUNBYN model

MUNBYN 4x6 Example: ITPP941-USB

Connection, example model
USB
Resolution, example model
203 DPI
Max print width, example
108 mm
Feed, example model
External roll; fanfold unverified

Who it's for: You can match a listing's model code to a USB shipping-label printer and its driver.

Skip if: The listing does not identify the model. Other 941 versions have different connections; these facts apply only to ITPP941-USB.

Manufacturer model specifications

Check price on Amazon

DK roll labels and a cutter

Brother QL Example: QL-1100

Connection, example model
USB / USB host
Resolution, example model
300 × 300 DPI
Max print width, example
4 in
Feed, example model
Brother DK rolls

Who it's for: You want cut labels and plan to use the compatible DK stock system.

Skip if: You need generic fanfold stock. Many smaller QL models cannot print 4x6; the specs here describe QL-1100 only.

Example model specifications · QL model differences

Check price on Amazon

Your printer shortlist

Read the model qualifications and check the exact listing before buying.

Choose label stock before you buy

Match the printer's supported width, material and feed type first. A printable PDF size does not prove that your printer can feed that stock. Rollo uses direct thermal paper with gaps or perforations; DYMO 5XL and Brother QL models have their own label requirements.

Affiliate links: As an Amazon Associate I earn from qualifying purchases. About shopping links.

  • Compare 4x6 labels on Amazon for printers that support generic direct thermal stock. Check roll or fanfold feed and the exact dimensions; these are not a universal DYMO or Brother supply.
  • Compare 2x1 labels on Amazon for item numbers or product labels. Confirm your printer's minimum width and height, then print the 2x1 PDF at Actual size.
  • Compare label holders on Amazon if your printer feeds labels from behind. Check roll diameter, core size and desk clearance. Internal-roll printers may not need an external holder.

Read the manufacturer's requirements: Rollo label stock, DYMO 5XL labels and Brother QL model widths. Try the stock you already have before buying replacements.

Choose the tool for your labels

Your jobToolBefore exporting
Number warehouse shelves or binsBin LabelsCheck the range and choose portrait or landscape.
Prepare numbered Whatnot lotsWhatnot LabelsCheck sizes and fix tiny prints before running your batch.
Print an existing Amazon FNSKUFNSKUCopy the identifier from Seller Central; this tool does not issue FNSKUs.
Make a custom barcode or warning labelEditorSelect the media preset, then add text, barcodes, or artwork.

Test before a full run

Inspect the PDF, print one page, and scan any barcode before printing the rest. A downloaded PDF can be printed again as many times as you need. Label Ninja creates label artwork; it does not purchase shipping postage.

Thermal label printer FAQ

Why is my 4x6 label printing too small?

The print dialog is usually scaling it down. Choose the exact 4x6 paper size, set margins to none, and set scale to 100% instead of fit to page.

Why is my thermal label printing sideways?

The driver orientation does not match the label design. Change Portrait/Landscape in the print dialog, then choose the matching Label Ninja layout.

Why is my label printer feeding blank labels?

Blank feeds usually mean calibration, wrong media sensing, upside-down thermal labels, or the wrong label type in the driver. Recalibrate after reseating the roll.

What printer should I buy for eBay and Amazon labels?

For 4x6 shipping labels, choose a printer that supports a 4-inch print width and the stock you plan to use. Compare its connection type, current driver support and label requirements in the printer checklist above.