@sadmonkeymerc ;

Did you try following the label printing help posted by @Helen ?

Since the OP did not respond to her since her post I am wondering if this solved the problem.

If not, I use the Zebra 420 printers for my barcodes, which print fine but I use the Zebra software to create my barcode labels.  I can add a lot more information and set the labels up the way I want them to appear etc. plus choose different barcode fonts that work with my scanner, such as using a QR code or Aztec code for my 2D scanner along with the Code 39 or Code 128 barcodes.

Just options for you before you struggle.  Also depending on Barcode your trying to print enlarging it or reducing it can make it blurry

Hi @Candlestore, thank you for the response! I have run through the troubleshooting steps but unfortunately have not found a solution. I think the PDFs created by Square are just a low quality. I have tried raising the DPI but that just "zooms the image in" if that makes sense, and I am on a Mac so the Zebra software is unavailable. I suppose I could look for another Mac-friendly software but I don't believe Square exports the barcodes in a format other than PDF. How do you import your barcodes into the Zebra software?

The barcode scanner I have DOES read the ones I am able to print, but they just look crappy which is frustrating after you pay a lot of money for a nice printer. Anyway, thank you again and if I find a solution I'll be sure to follow up!

@sadmonkeymerc ;

I import them by typing them in.  The only barcodes I need are for items that do not come with them or items I make to sell.  So I open the Zebra Designer software, click on the barcode icon to insert a barcode, choose the Barcode I wish to use, and then in the one field it says source I believe and I type in the code I want to use for the barcode.  After creating the barcode for the item, I save it to a folder on the desktop connected to my label printers for future use.  Then if I need more I open the file and just tell it to print X number of labels.  I also print one out go to my Square stand scan it and add the item. This way I can check to make sure the barcode reads and to make sure the barcode is what I wanted.  I already have typed the barcode in and spelled a word wrong or my chubby fingers hit extra keys, or I pressed <enter> after my text for the barcode and the enter button created extra characters in my barcode.

Now if you want you can spend some money to upgrade the Zebra Designer 3 software to a pro version for about $300 I believe.  By getting the pro version you can import a csv file as a source for basically a mail merge type operation with the Zebra Designer 3 Pro version.  So in your label design you can have areas for <Item> , <price>, <UPC>, etc and where ever the <UPC> is it will match the <UPC> to the UPC in Square to print on the Label.  This is what I saw in a YouTube video but have not invested in the Pro version myself. 

here is a video showing how to connect Zebra Designer 3 to a database (csv, Excel etc)

https://www.youtube.com/watch?v=jTT5OuKURqI 

Since your on a MAC, I am not sure if a windows emulation program would let you run Zebra Designer 3 and Pro versions.  Just an Idea to try.

Now while I was looking this information up about Zebra Designer 3 for Mac I did come across this program for a 1 time fee of about $150 that works with windows and mac.  It has a 14 day free trial to see if it does work and has an csv, excel integration to read from your Square Items export.  Here is a link to that if you would like to look into it....https://label.live/  

Here are the Zebra printers supported with this software:

https://label.live/zebra-printer-software 

@Candlestore 

Thank you for such a detailed response and all of your input! That is VERY kind of you to take the time to help me find a solution. I downloaded the trial for Label Live and printed out a sample barcode but it was ALSO fuzzy. I uploaded a photo to show the results here: https://imgur.com/yAZ5EV5

The top barcode is from the printer's test print - the middle is from the Live Label software (with its watermark) - and the bottom is from the Square-generated PDF. 

I just found a YouTube video that mentions a driver you can buy for $97 that fixes the issue: https://www.peninsula-group.com/mac-thermal-printer-driver/download-thermal-driver.html

I downloaded the demo and it DOES clear up the barcode, so my conclusion is that the built-in Mac driver does not communicate well with the Zebra printer and needs a custom Driver. But rather than purchasing the Peninsula driver for $100 bucks, I think I am going to return the Zebra printer on Amazon and purchase a DYMO one instead. I like the size of the Zebra labels better, but I think we can make the DYMO sizes work.

Thank you again and I wish you all the success with your venture!

@sadmonkeymerc ;

With the DYMO software you can export your items file from square and use it with the DYMO software to print labels if it does not work natively with Square.  I just wonder why Zebra does not work well with Macs?  

Here is a video for importing csv / excel files with the DYMO software:  Dymo Software with Spreadsheet data 

Good Luck getting everything to work for you!!!