Make the test sheet boring.

Save the data as CSV or TSV with one header row. Keep the barcode value in a dedicated column and use separate optional columns for a title, subtitle, and copy count.

• Code 128 accepts general text.
• EAN-8, EAN-13, and UPC-A require the correct number of digits and a valid supplied check digit when one is present.
• QR, Data Matrix, and PDF417 accept broader text, subject to the app's visible length checks.

Choose the matching built-in sheet size, then set the first unused label position. The preview leaves every earlier position empty. Confirm the complete sheet before export; SheetMark does not know which physical labels have already been removed.

1. Export the calibration proof and print it on plain paper.
2. Disable “fit to page” or scaling in the PDF print dialog.
3. Hold the proof behind the label stock and measure consistent X/Y drift.
4. Enter the offsets and scale correction, then repeat the proof.
5. Scan several codes before a production run.

After a completed checkout, keep the same browser tab open. The license page retrieves the key through that tab's secure session; it never puts a transaction or claim credential in the address. Copy the key into Pro license → Activate Pro in the Windows app.

The lifetime license supports up to three active Windows devices. Choose Deactivate this device before moving a seat when the old installation is still available. The app can continue through a 30-day offline validation grace period after a successful online check.

For security, SheetMark does not offer transaction-only key retrieval. First return to the same tab within ten minutes and useTry again. If the tab or session is gone, email support with the Transaction line from the Paddle receipt and the visible error text.

Do not send card details, a CSV/TSV, barcode value, project, PDF, SVG, license key, claim credential, or customer data.