Help please! Printing with HP B8850.

I wish to print an image : 19,7 x 29,47cm on an A4 size sheet of paper = 21x29,7cm, so that it comes out full size, with nothing missing from the print, not even 1 mm.

This would perfectly fit into the mat without any white showing.

Is it possible to do this, please? and if so how?

I'm beginning to think that my HP B8850 can't do this and that the only way is to use/waste larger paper than A4 to get the result that I want... as I have tried a few different ways without success for the moment.

Thanks for any help.

Miralee