As VanKalkerFarms answer states, Point of Sale is not compatible with standard desktop printers at this time. A possible solution might be to view your receipts on your online Dashboard after the transaction is complete and you can print them from there on a desktop printer. 
It has 5 bill trays, 5 coin trays and a bill entry, keeping your money organized and largely improve your working efficiency and accuracy. Electronic Cash Drawer There are 5 bill trays and 5 coin tray…
The new Square Contactless and Chip Reader is included so you can accept every way your customers want to pay. Place the reader in the dock, connect the dock to the USB hub, and you’re ready for business. Accept magstripe cards, chip cards, and NFC payments like Apple Pay.
Another nice touch is that they include a CD which allows you to customize the printer (add logos, sync with POS systems, custom data to add once the receipt is printed, etc). Keep in mind though, this customization works with certain POS systems, not all. On Square, I can’t tell the printer to print out all of the extra stuff since the POS for Square is very simplified.

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Built specifically to work in environments where heat and humidity can erode the type on the kitchen order, the SP700 is an ideal printing solution. This fast, two-color printer offers crisp, easy to read type for quick viewing, clamshell design for easy paper loading and an embedded power supply for space efficiency.
To create your own bar codes and labels, you’ll need to use a third-party application. At the moment, we don’t support bar code and label printers and can’t guarantee compatibility, but many customers have success using the DYMO Label Writer 450 and labels with Square.
SQUARE and SHOPIFY POS BUNDLE INCLUDES: • Square and Shopify recommended Star Micronics TSP654IIBI-24 Wireless/Bluetooth receipt printer. • Shopify/Square recommended printer driven 16X16 Cash Drawer. Comparable to APG 16×16 Vasario Series Cash Drawer Part #: VB320-BL1616 The compact footprint fits easily on your countertop and saves precious counter space. The clamshell design allows for fast and easy paper and ribbon loading. This printer can print 60 receipts per minute via Bluetooth connection, so you can tackle your daily needs with ease and efficiency. Pair it to your Shopify POS without a Wi-Fi connection. Need more counter space? Mount the printer to the wall with the included wall mount bracket. • Avoid complicated network setups – simply sync via Bluetooth, and you’re ready to print receipts from your iPad. • Uses thermal printing technology, so you’ll never need expensive ink or toner. • The Retail Package upgrade is required for this to connect to Shopify POS. Recommended for merchants who are looking for an easy to set up, reliable receipt printer.
SM-T300i Mobile Printer (SM-T300I2-DB50 US GRY), 3-Inch Print Width, Bluetooth 2.0, Serial Interface, (Includes Serial Cable, Battery Pack, AC Charger, Sample Paper Roll), Color: Gray (Part Number: 39634010)
Bluetooth printing was a great project — it brought many unique engineering challenges and taught me a lot about how Square’s code base works. I’ve always been taught to use inheritance when possible to organize and share code, but working with the peripheral class hierarchy was a strong reminder of just how valuable a good, well-organized, object-oriented architecture can be. There was a lot of shared code between WiFi and Bluetooth printers that I could have copied and pasted, but I’m glad that I took the time to not just make it work, but to do it right. I’m thankful that my co-workers pushed me to take the time to experiment with different abstractions of concurrency. Not only is my code better, but I now know many ways to approach the problem. In software, there’s rarely just one solution, and this is a good reminder to explore every possibility before choosing one — because it was the first idea that seemed to work.
Just click the Transaction and the Receipt will preview on the right-hand side. At the bottom, you’ll see the receipt number (ex: Receipt #H8R5). Click that and it will show you the digital version of the receipt. From there you’re good to print on the standard 8×11 printer paper.
Native Technology, Inc. is a third-party hardware reseller and is in no way affiliated with Square, Inc. Native Technology offers POS hardware that is compatible with the Apple iPad and Square, Inc. products. Square, the Square logo, Square Register, and Square Reader, are registered trademarks or trademarks of Square, Inc. iPad™ is a trademark of Apple Inc. iPod touch®, and iPhone® are registered trademarks of Apple Inc.
My first inclination, having just taken a class in C++ using pthreads, was to simply use locks. I created a shared NSLock through a class method and locked before listening and printing, as described in Apple’s Threading Programming Guide. I was excited when it accomplished the mutual exclusion I wanted, but my coworkers were less thrilled about using such a low-level solution given the higher level abstractions available in iOS. In search of a higher-level solution, I replaced the global concurrent queue on which I was running the printer code with a serial dispatch queue, allowing only one block to be run at once. I was getting warmer, but my new solution still raised some concerns.
Pos thermal printer with high speed and advanced technology. Or add greetings as well! Works with all pos softwares. easy installation and if you prefer, TPG technicians will walk you through on how t…
Don’t forget, we also sell Square Compatible Hardware Bundles for all these printers that includes s Refurbished Receipt Printer and a New compatible cash drawer plus cables, paper and everything you need to get started!
The Ethernet printers compatible with Square Point of Sale are thermal printers. They require heat-sensitive paper and won’t work with non-thermal receipt paper. These types of printers aren’t ideal for kitchens or high-temperature working areas. 
Complete your countertop POS system with this Square register kit. Print paper receipts, daily sales reports and summaries right from your iPad. Includes, Square reader, Star Ethernet Printer, APG 13″ Vasario Cash Drawer, drawer cable, extra 2 rolls of thermal receipt paper and installation support. 
Square Point of Sale on an iPad is compatible with a wide variety of third-party hardware accessories. Below, you’ll find a list of supported accessories, where to purchase them, and information on getting set up.
With your choice of one or two under till media slots, the Series 4000 makes safely storing receipts, large bills, or other important media a snap. The spacious heavy duty till features coated bill stays and stronger than average dividers, so you can be sure your money stays put.
If you have a Square Stand, in addition to the printers above, you can use certain USB interface receipt printers. The following receipt printers are only compatible with the Square Stand, not the Square card reader:
I do appreciate your post though and I wanted to let you know that we are working to provide support for more printers and your feedback is welcome! For example, we recently launched support for several Epson printers which can be used with Square on iOS devices (the full list of printers is here). 
Everything you need to get started taking in orders and money (except the iPad and the cash for the till!). Includes, Square credit card reader,  receipt printer with Ethernet interface, 2 rolls of receipt paper, 13″ wide cash drawer with till, and all cables for connecting the printer and cash drawer.
The STAR MICRONICS SM-T300I is also a light weight receipt printer. But it’s very durable and rugged. It’s also Apple MFi certified for iOS phone and iPads. It also works with Android and Windows. It’s been tested to take a little bit of beating and is used by people who are outside a lot. Having said that the price is higher than other printers. If you need something rugged, this device may be the one for you. But if you don’t. You will want to look at something else as this device can get expensive. The SM-T300i is easy to use. There is a well written and very detailed user manual. The user manual gives details on how to configure the receipt printer and how to load paper. Here is a link to the Star Micronics SM-T300i User Manual.
Electronic Cash Drawer It has 5 bill trays, 5 coin trays and a bill entry, keeping your money organized and largely improve your working efficiency and accuracy. 1 Cash Drawer. Only the cash drawer is…
Send invoices free from your Square Point of Sale and get paid faster. Customize your invoices, set up weekly or monthly recurring invoices from your Dashboard, and let customers pay online with a credit or debit card. Invoices are free to send and cost 2.9% + 30¢ per invoice paid online.
It has 5 bill trays, 5 coin trays and a bill entry, keeping your money organized and largely improve your working efficiency and accuracy. There are 5 bill trays and 5 coin trays, with a bill entry, y…
If you’re not satisfied, neither are we. Bottom line, we want you happy! We will make every attempt possible to resolve the issue if we made a mistake. (It happens). Let us know if our service could b…
Did you just purchase a Square Stand or have the Square Register app running on your Android, iPhone or Tablet and need a Receipt Printer or Cash Drawer Hardware Bundle? There are a few different models and options for you to choose from when selecting a Thermal or Impact Receipt Printer and we will go over these here. We will cover other popular POS apps like Shopify, Breadcrumb, Shopkeep, PayPal Here and Clover in upcoming articles.
Edit to say that the network issues I mentioned were tied to the wireless router we were using. Replaced that piece and the printer started working great. I still recommend purchasing as a package for better price and customer service, but not a bad piece of equipment.
Square Register Star TSP654 LAN Thermal Receipt Printer with Auto-Cut, Ethernet/LAN Interface, Dark Grey Color, No Power Supply, No Interface Cable – TSP654L-24GRY – 37999540 **TSP654L-24GRY has been Discontinued – Replace with TSP654IIE3-24 GRY**
Buy Used and Save: Buy a Used “Star Micronics Monochrome Receipt Printer” and save 74% off the $690.00 list price. Buy with confidence as the condition of this item and its timely delivery are guaranteed under the “Amazon A-to-z Guarantee”. See all Used offers.