I coded a background using the same image from a Squarespace page. Then I was informed by the creator of the page that they just pulled it from Google, so I got to the image from Squarespace's source code, downloaded it and set it as my own background and it is pixelated.
I've searched the web for all the different background tricks and none of it provides anything like Squarespace's perfectly rendered background.
Does anyone have any suggestions as to how I can use the same image without it getting pixelated?
You cannot create something out of nothing.
If you do not have a vector copy of the photo, you cannot recover it without quality loss while enlarging the photo.
In such cases, you have to find an alternative (large one).
( 2000x2000 image => output 1200x1200 : no quality lost ) ( 1200x1200 image => output 2000x2000 : quality lost )
SquareSpace has large copy of that but you only can see what they put on client side and that is small one.