Thermal receipt printing

Printing bills on a 58 mm or 80 mm receipt printer at a shop counter, from setting it up to what the receipt shows.

#Setting it up

Install the printer in WindowsUse the driver that came with it, set the paper size in the driver to your roll width, and make it your default printer, or pick it in the print window each time.
Choose the receipt sizeOn an invoice, open Customize and set Paper / print size to 80mm Thermal or 58mm Thermal. The app remembers it for your next invoice.
Try a test printIn Print Settings, pick the Thermal (80mm) preview tab and click Test Print.
Print a real billSave the invoice, then click Print. A preview of the receipt opens; click Print again.

Picking the Retail Shop or Restaurant business type in Print Settings sets sensible receipt defaults in one go.

#The print preview

On a receipt size, Print shows the receipt at 160% so you can read it. Its buttons:

Print	Sends it to the printer. Shows "Sending…" while it works.
Download PDF	Saves and downloads a PDF instead, the same as Save & Download.
Cancel	Closes it. So does `Esc`.

#Printing straight after saving

At a busy counter, turn on Auto-print on save: Save & Download then prints the receipt as well, with no extra click. It can also be turned on for just one client, in their details.

#What a receipt shows

Your logo (if turned on in Print Settings), business name in capitals, tagline, address, GSTIN and phone.
The document type, such as TAX INVOICE, then the invoice number, reverse charge, date, and the client's name, GSTIN and phone.
Each item: its name, then quantity × rate, GST rate and HSN, with the amount on the right. The amount is quantity × rate, before discount and tax.
Subtotal, discount, CGST, SGST or IGST, cess, round-off and TOTAL.
Amount in words, bank details, a UPI QR code with "Scan to pay via UPI", and notes.
Your footer message, such as "Thank you for your business!", your email, the cut line and blank lines to tear against.

#What a receipt leaves out

To fit a narrow roll, receipts do not print: terms and conditions, the signature and stamp, extra pages, the due date, place of supply, client address, TCS, TDS, whole-bill discount lines, the exchange rate, watermarks, the reverse charge and composition notices, or the PDF style and colour. The custom invoice title is not used either.

If you need any of these, print that invoice on A4 or A5 instead.

#Changing how receipts look

Font, boldness, capitals, spacing, darkness, what is shown, the QR size, the footer message, the cut mark and feed lines are all in Print Settings, Thermal receipts.

#When a receipt prints badly

Problem	Try
Text is cut off on the right	Use a smaller printable width: most 80 mm printers print 72 mm, and most 58 mm printers print 48 mm. Use Custom size if yours differs.
Print is faint	Set Font weight to Bold or Ultra bold, and Thermal ink darkness to Dark.
The printer jams or stops half-way	Turn on Buffer-safe mode.
Blurry text, or nothing prints	Set Thermal print method to Via PDF.
Paper does not feed far enough to tear	Increase Feed lines after cut.