Using HTML to size a QR Code from a Formula Rich Test field

I use QR Codes in almost all of my apps.  Of course I found out how to do that here!  But I can not seem to change the size for printing using exact form.  Would it be possible to add HTML formatting in that formula rich text field to the change the size of that generated code or possibly in another formula rich text field that calls the QR Code field. 

PS I am not a coder and have very little experience with HTML. 

Thanks in advance!

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Julie Meeker
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