Will background color print?

[hsmokey]

Hi there,
We have a piece of art we're trying to edit and then save and print- We would like it to be a certain size but, as is, there is a gap between the size of the artwork and the 'background'. We would like to change the background color to match the border of the artwork, however, are unsure if the background color will actually save and print since it's not the same layer (or maybe not a layer at all?). Does anyone know if the background color will in fact save as displayed and print that way? Please see attached image for reference-

Thanks!